GTA
All Springer/NP/PCP Air Gun Discussion General => PCP/CO2/HPA Air Gun Gates "The Darkside" => Topic started by: mooseslayer on February 21, 2016, 12:16:50 PM
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Time to start one. I have been working on an SSG for my .22 disco. When I first got it I was disappointed with the 14 or so usable shots. In the past I have tried with my diy PA and some porting of valve, thinning poppit, and different tport sizes to try to get over 20 shots with jsb 15.9 at 800-850fps. I am a rookie at this and nobody up in my area that I know doing this stuff so flying by the seat of my pants.This is just what I want for hunting small game. I have come close to it. I had drilled out my endcap long ago and threaded so I could change springs on the fly so Bob's first SSG was easy to adapt to. I tried Bob's first SSG 3inch and used my existing .040" thick springs in varying lengths but power dropped was first in mid 600fps. I made a new longer one and a couple of springs and even welded a 3/8 nut to the back of my endcap to be able to use the longer ssg before coil bind. I got back to 750fps and got a ton more shots. I am waiting on order for 10" long .312 springs n .037, .041. .047 and .055 for testing.
Here is the string I just shot jsb 15.9. almost at coil bind and small gap.
1 744
2 741
3 743
4 748
5 742
6 744
7 740
8 744
9 749
10 747
11 744
12 747
13 750
14 749
15 747
16 754
17 751
18 746
19 740
20 742
21 741
22 737
23 746
24 743
25 737
28 737
29 722
30 729
31 728
32 726
33 719
Not sure where to cut it off but I have never got near this many shots before the SSG.
Still want to get power back but this is a start. I made this really long bastardized SSG for testing and still ave the original 3" one. I am hoping to consolidate everything once I get new springs. I am sure I will get this shorter, but if I increase shot count dramatically and it sticks out the back, I will just make some sort of shroud for it.
Here is my bastardized version of SSG. It is under almost an inch of preload.
(http://i1305.photobucket.com/albums/s560/mooseslayerjc/IMG_20160221_100829_zps6cqaiqvd.jpg)
(http://i1305.photobucket.com/albums/s560/mooseslayerjc/IMG_20160221_101740_zpsuvlajgdk.jpg)
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Just as a reference, I was getting about 17-18 shots with same pellets at 810fps avg before SSG. I dug up a string from last fall (been too cold to shoot here in southern Ontario).
797.00 821.00
797.00 819.00
800.00 817.00
805.00 802.00
810.00 812.00
813.00 805.00
813.00 799.00
820.00 786.00
825.00
829.00
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Play with spring weight or SSG tension maybe?
Cheers
Jay
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In case you don't already have it here is the best(imo) efficiency calculator . Seeing that it's free online, I don't think Lloyd would mind.
http://www.calc.sikes.us/1/ (http://www.calc.sikes.us/1/)
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oops...just realized I missed shots 26 and 27
Here is the string I just shot jsb 15.9. almost at coil bind and small gap.
1 744
2 741
3 743
4 748
5 742
6 744
7 740
8 744
9 749
10 747
11 744
12 747
13 750
14 749
15 747
16 754
17 751
18 746
19 740
20 742
21 741
22 737
23 746
24 743
25 737
26 744
27 737
28 737
29 722
30 729
31 728
32 726
33 719
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So you lost some power but gained many shots. I think this is quite typical. To get it back, are you going to try stiffer springs since you're already at coil bind?
I have made one like yours using a Prod cap but haven't had a chance to test it yet. But.... I've already thought of a new design based on another version a vendor is selling for the Mrod. It will cost me more parts from Crosman in the way of another Prod hammer weight which I will have to machine for the rear breach screw for clearance but it will be all internal design. Also the weight from the rod is part of the total hammer weight.
I can't wait for the weather around here to break but I know it's going to be three weeks or so at least. You're north of me but not too far. I'm down in SW Michigan. Late March we should be back to shooting outdoors.
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I have springs ordered in .037 .041 .047 and .055 to test....and yes, hoping to increase power with them. I was hoping to see what others are doing with disco SSG in this thread. I love that it is evolving from Bob's first SSG.
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You do need a slightly stiffer spring with fewer coils. Your biggest problem is your spring has far to many coils and also try polishing your hammer tube with a ball hone it will add more FPS at no cost and make cocking smooth like gravy.
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You do need a slightly stiffer spring with fewer coils. Your biggest problem is your spring has far to many coils and also try polishing your hammer tube with a ball hone it will add more FPS at no cost and make cocking smooth like gravy.
I will have to save this tip and try it myself for sure. So less coils and hammer polish?
Cheers
Jay
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The hammer tube area as seen in first video here... http://wickedairrifles.com/installation-instructions.html (http://wickedairrifles.com/installation-instructions.html)
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I polished that area a while back but not sure how smooth. I think I used a dowel in drill with notch for sandpaper. Maybe ill do again. Got up to 1500 wet dry and some ultimox. Thanks Oldpro. Springs will be here next week
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The hammer tube area as seen in first video here... http://wickedairrifles.com/installation-instructions.html (http://wickedairrifles.com/installation-instructions.html)
Same thing applies for the disco Im assuming?
THanks Travis
Jay
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The hammer tube area as seen in first video here... http://wickedairrifles.com/installation-instructions.html (http://wickedairrifles.com/installation-instructions.html)
Thanks Travis - I'm totally doing this to my Disco. Also my brother's Mrod when we tear it down next time.
Nice work on the Youtube vids and the online instructions by the way.
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Follow up question - what grit do you use or recommend?
I'm looking at 400 grit.
And actually the Disco I believe is slightly smaller ID so I would assume a 1" is a little big.
I forget the dimension but I will measure mine first.
Thanks
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May try this on sons Disco. I measured everything in the air tube from the valve stem to the end of cap. Gun apart and spring out and measured everything with dial caliper. the total length from bottom of hammer hole to bottom of cap hole was 1.575 with hammer touching stem and cap sitting in tube. Can you take this length and subtract .020-.040 and make SSG that long. My spring at rest is 1.940 so it is being compressed around .365" when assembled. Will I need a new spring to do this. What end cap mods need to be made to try to keep it mostly internal. Any idea on when a WAR SSG will be available for Disco if I mess this up.
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Excuse my ignorance, but what does SSG stand for?
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A few months back, Bob Sterne designed and implemented a Spring Stop Guide, which basically stops the hammer spring just shy of the hammer when it opens the valve and reduces/eliminates hammer bounce, which in many cases is a huge waste of air. This makes the pcp more efficient and you can get more shots per fill. It is brilliant and I think the biggest rage lately as many are designing different and better versions of it. Do a search and you can find more information. I think the original thread is 38 pages long.
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Here is the original thread if you have some time to read 39 pages of posts lol.
http://www.gatewaytoairguns.org/GTA/index.php?topic=102095.0 (http://www.gatewaytoairguns.org/GTA/index.php?topic=102095.0)
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Thank you sir.
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May try this on sons Disco. I measured everything in the air tube from the valve stem to the end of cap. Gun apart and spring out and measured everything with dial caliper. the total length from bottom of hammer hole to bottom of cap hole was 1.575 with hammer touching stem and cap sitting in tube. Can you take this length and subtract .020-.040 and make SSG that long. My spring at rest is 1.940 so it is being compressed around .365" when assembled. Will I need a new spring to do this. What end cap mods need to be made to try to keep it mostly internal. Any idea on when a WAR SSG will be available for Disco if I mess this up.
If internal design is your plan, the factory end cap should be usable.
It comes with a threaded bore for a spring guide or a de-gassing tool which could be used for an adjustable stop for the SSG rod.
With internal design. the SSG rod rides through the middle of the hammer weight and the end of the SSG rod on the face side of the hammer weight is actually what strikes the valve when you fire. This is how I understand it and until I build my own, I won't have any measurements or part suggestions. By then, Old Pro Travis will have his to market already. Tricky parts might be hardening the end of that rod which also must have a larger end on it. I'd like to turn this on a lathe and heat treat it ideally.
Or just by it from Travis when he releases it.
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Do you think there is enuff room inside the Disco fro this to work. Or is that not a concern.
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Ok...I polished my hammer and hammer tube area to a mirror finish starting 320grit up to 1500 grit. I lubed with some powdered graphite I had. I also drilled out my endcap so no possible friction for SSG there. The 3/8 nut welded on endcap is holding SSG 3/8 bolt. I also drilled and tapped my valve to 10-32 and installed high tensile screws. Then I filled to 2300psi and shot first shot with no gap so SSG basically non existent...hit 930fps with 15.9 jsb and loud. I turned SSG so small gap and shot some shots and the turned in another half turn, refilled to 2300 and shot a string down to about 1000.
Here is that string.
1 – 758 11 – 759 21 – 758 31 – 747
2 – 747 12 – 761 22 – 755 32 – 750
3 – 749 13 – 752 23 – 756 33 – 745
4 – 754 14 – 755 24 – 757 34 – 743
5 – 753 15 – 762 25 – 758 35 – 735
6 – 756 16 – 762 26 – 759 36 – 735
7 – 755 17 – 765 27 – 758 37 – 730
8 – 759 18 – 761 28 – 755 38 – 726
9 – 761 19 – 757 29 – 753 39 – 721
10 – 759 20 – 761 30 - 756
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I can barely get that with double tube Disco. Is your single tube. Those are awesome results. Imagine the shot string with SSG and double tube. My son could shoot all day.
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yes. single tube
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That's 36 shots under a 4% ES that's very good results.
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Anyone ever drill out Disco hammer. I am assuming it is very hard. Want to drill thru for an SSG attempt. Would that remove too much weight and render the ssg useless.
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dpittman
You can buy a crosman challenger hammer assy for 21.76 plus 4 bucks shipping from them that already has the hole for the stroke adjustment screw in it and then just drill out that hole and install the spring guide rod SSG adjustment screw and away you go. Just call them buy phone to get flat rate 4 buck shipping regardless of order size or cost.
The hammer is hardened on the surface and you will wear out several drill bits before you get it drilled out or end mills if you are going to use a mill. for 26 bucks it much easier to buy the Challenger/prod hammer and be done with it.
Mike
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Thanks Mike. Good to know. I was thinking same.
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dpittman
Not a problem
Mike
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it's fairly easy to drill a crosman hammer
all you need to do is remove the case hardening with a carbide rotary bit then it can be drilled or machined(remember to do both ends if drilling)
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That's true but not everyone has a grinder or carbide dremel tool bit plus I believe the challenger/prod hammer is a bit heavier than the stock 22xx/13xx hammer is so it will have more inertia.
Mike
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Can't it be heated up cherry red and air cooled to drill?
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Yea you could heat it cherry red but then you loose all temper in the metal and it could distort some as well so it would not be the exact same dimensions as before possibly. it would be better to oil cool it if you do it that way to retain some of the temper.
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it's made from low grade steel so to re harden you would have to use kasenite or similar
the carbide burrs are a few quid
just to see I took a stock disco hammer and drilled it m5 and a 8mm counter bore to sink the head of a m5 bolt iturned down to 7.5 mm
took about 15 mins to do
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Anyone ever drill out Disco hammer. I am assuming it is very hard. Want to drill thru for an SSG attempt. Would that remove too much weight and render the ssg useless.
Someone else may have more information or correct me if I'm wrong but check this out.
The Prod hammer weight will work in a Discovery. This is what I'm using. You will need to clearance it at the top at the nose to clear the back breach screw. Norm at Discosrus sells these weights machined and ready to go for use with the Challenger trigger assembly for which they are required. Also required is a spacer for the trigger assembly.
That aside, the 2260 trigger in the disco might not work with a Prod hammer. I don't see how it could work actually since the sear engagement is different between the two and the Prod weight has no notch in the body. The sear is designed to engage the face of the weight with the triggers for this design.
Otherwise, as far as machining, I had a pretty easy time clearancing my prod hammer weight with a carbide end mill. I went slow and used cutting oil and it was a piece of cake. If you however take a HSS drill and try to cut this case hardened part, you will just destroy your bit.
I would want a lathe to drill a nice, straight, centered hole in that weight using a carbide tool.
As for weight difference with the SSG if you're using the design that has the SSG rod as part of the hammer weight ( internal design ) you are adding weight to it, not making it lighter.
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it's made from low grade steel so to re harden you would have to use kasenite or similar
the carbide burrs are a few quid
just to see I took a stock disco hammer and drilled it m5 and a 8mm counter bore to sink the head of a m5 bolt iturned down to 7.5 mm
took about 15 mins to do
Was that done by hand or in a mill
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in a lathe but I could have done it in a drill press nearly as easy
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Agreed that a drill press would be about as easy just not as precise as a lathe since you have much better control over speeds and feed rates in a lathe than a drill press as well as equipment tolerances.
Mike
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Ped, that is exactly what I want to do for an internal Disco SSG. That looks awesome. The only diff would be my bolt head would not fit inside the hammer face like yours. Great work. I was also wondering if you have to mod a challenger hammer fro how it cocks the gun. In other words does the challenger hammer drop right in or need mods.
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Steve, I just re-read your post and it looks like you have to have a MROD trigger for the challenger hammer to work in a Disco. Is that correct. I have the regular Disco trigger group.
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challenger/p-rod hammer is a drop in unit in all the crosman 22xx and disco guns and will work with std triggers
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Steve, I just re-read your post and it looks like you have to have a MROD trigger for the challenger hammer to work in a Disco. Is that correct. I have the regular Disco trigger group.
Indeed I have the Mrod Gen1 / Challenger trigger group on my Disco using a Prod hammer weight.
I also put the Challenger guard on my trigger.
As far as I have been aware, the OEM Disco trigger uses the same style of sear engagement as the 13xx trigger group and requires a weight with a notch in the middle for the sear to catch. Trigger groups that engage the face of the weight are Mrod, Prod, Challenger, and 1701P.
The weights for these triggers don't need the notch but it can be used with them. If you use a notched weight, the notch can strike the sear and damage it over time after shooting. I have built a 13xx using a filled weight and later an upgraded solid stainless weight with a 1701P trigger and it was very nice.
Note the challenger weight on the left and the Disco on the right.
That said, the Challenger trigger upgrade while pricey in my opinion is very nice, and a much better trigger than the OEM Disco. I even had the brass upgrade for awhile which was much better. For the cost of the whole Mrod trigger conversion I could have bought a 392.
So if you go this route using the Challenger weight, be aware the potential issue. I've never tried using a challenger weight with 2260 trigger.
(http://i7.photobucket.com/albums/y297/pad617/strikers.jpg)
(http://i575.photobucket.com/albums/ss198/braumeisterwurf/DiscoChallengerTriggerInstalled.jpg)
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The notch (waist) in the middle of a Disco/22XX, or a 13XX hammer serves NO useful purpose (except to hold the hammer off the end of the valve if you pull it back just a small distance).... The sear does NOT engage there when the gun is cocked, it engages on the front of the hammer, in exactly the same place as does the PRod, Challenger and 1701P hammer.... The MRod hammer also engages on the front....
If you use the PRod or 1701P trigger group on a 13XX, Disco or 22XX, you must use the corresponding hammer, WITHOUT a notch in the bottom, or fill the notch in, or you will have to pull the trigger in order to cock the gun.... I have made many cylindrical hammers for 13XX, 22XX and Discos, for use with either the standard trigger or an MRod trigger, and I can assure you that they work perfectly.... The notch (waist) is NOT required....
Bob
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The notch (waist) in the middle of a Disco/22XX, or a 13XX hammer serves NO useful purpose (except to hold the hammer off the end of the valve if you pull it back just a small distance).... The sear does NOT engage there when the gun is cocked, it engages on the front of the hammer, in exactly the same place as does the PRod, Challenger and 1701P hammer.... The MRod hammer also engages on the front....
If you use the PRod or 1701P trigger group on a 13XX, Disco or 22XX, you must use the corresponding hammer, WITHOUT a notch in the bottom, or fill the notch in, or you will have to pull the trigger in order to cock the gun.... I have made many cylindrical hammers for 13XX, 22XX and Discos, for use with either the standard trigger or an MRod trigger, and I can assure you that they work perfectly.... The notch (waist) is NOT required....
Bob
Hey Bob,
Thanks for clarifying for and helping me understand as well.
Poster ped - I wasn't doubting your advice, I'd just never heard of using non-waisted hammers with these triggers and obviously misunderstood the sear engagement.
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I was thinking the waist allows air movement(vent) from hammer foward travel thru notch to prevent compression and loss of hammer speed. It has to go somewhere.
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Prod trigger assy from crosman is only 36.50 and Mrod trigger assy is only 48.93 with 4 buck flat rate shipping for both so IMO they are not pricey at all for what you get as I am building a disco tubed, 3000 psi, challenger hammer,spring and RVA, Prod triggered, 1399 stocked, steel breeched, daisy Avanti 20 inch LW barreled, FT gun right now and have less that the price of a new disco in it so far and fully expect it to shoot circles around any disco as well as get twice the shot count.
Mike
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woohoo...springs are here. Four 10 inch .312 OD in .037, .041, .047 and .055 wire thickness. Hopefully I will have time to play this weekend.
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Im ready to see some results
Jay
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I forgot...pictures or it didn't happen...
(http://rs1305.pbsrc.com/albums/s560/mooseslayerjc/IMG_20160304_080309_zps8dvj4lrx.jpg~c200?t=1457024416)
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Waiting for results on testing.
Mike
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it's made from low grade steel so to re harden you would have to use kasenite or similar
the carbide burrs are a few quid
just to see I took a stock disco hammer and drilled it m5 and a 8mm counter bore to sink the head of a m5 bolt iturned down to 7.5 mm
took about 15 mins to do
. Does this protrude when cocked?
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It has to as I see no other way for the spring to be compressed without it protruding from the front of the hammer and when fired the hammer moves forward on the guide until they hit the valve stem as one unit with zero preload behind the hammer after released by the sear. IMO
Mike
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Ok...some preliminary testing with new springs. There are so many factors that can vary the results so I started with a goal of about 800fps with jsb 15.89 to get me about 22 -23 fpe on disco .22
The .037 springs too light...was in high 600fps range with a 3" spring so didn't even shoot strings.
The .041 spring I did a couple quick tests which were similar to my first ones with .040 so I decided to leave and test more later.
On to the .047 springs...started about 3" long so lots preload, very hard to cock mid 800fps but descending string, so start cutting coils and trying until I got just over 800fps and strings not descending. I ended up with 2.35 inch long spring and started testing.
Test 1 - fair amount of preload, close to coil bind, small gap 2300 - 1400 JSB 15.89 2.35, .047 spring
1-813
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oops...try again.
Test 1 - fair amount of preload, close to coil bind, small gap 2300 - 1400 JSB 15.89 2.35, .047 spring
1-813 11-821 21-806
2-816 12-819 22-805
3-818 13-820 23-800
4-821 14-821 24-802
5-820 15-819 25-793
6-819 16-814 26-788
7-813 17-810 27-787
8-819 18-818 28-782
9-821 19-809
10-821 20-811
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Test 2 - same preload, dial in nut on SSG to create bigger gap 2300 - 1500 JSB 15.89 2.35, .047 spring
1-795 11-809 21-807
2-797 12-812 22-807
3-800 13-813 23-799
4-796 14-814 24-801
5-802 15-815 25-795
6-808 16-808 26-792
7-808 17-807 27-788
8-805 18-809 28-786
9-807 19-806 29-784
10-807 20-805 30-777
so just changing the gap can make a difference
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Test 3 - dial out nut 1 more full turn so bigger gap 2300 - 1400 JSB 15.89 2.35, .047 spring
Note ...all my adjustments one full turn on bolt (preload) and nut (gap so there is a lot of room for minor adjustments to meet your specific goal. Changing the gap here didn't do a lot.
1-792 11-800 21-803
2-798 12-803 22-805
3-808 13-814 23-795
4-799 14-815 24-802
5-801 15-809 25-803
6-798 16-799 26-790
7-793 17-801 27-792
8-804 18-796 28-786
9-795 19-800 29-774
10-799 20-808 30-768
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Your 2nd string is definitely the best. 29 shots with a 3.8% ES.
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Test 4 - dial 3/8 bolt out one full turn easier to cock, less preload, small gap 2300 - 1400 JSB 15.89 2.35, .047 spring
Less power but more shots...I kinda like this string and near my goal and very consistent.
1-774 11-776 21-779 31-777
2-768 12-783 22-778 32-777
3-775 13-775 23-778 33-776
4-772 14-780 24-779 34-777
5-771 15-782 25-779 35-768
6-780 16-772 26-780 36-771
7-771 17-783 27-779 37-764
8-774 18-782 28-776 38-763
9-783 19-786 29-783 39-761
10-777 20-785 30-777 40-757
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Test 5 - same preload as #4 but 1 full turn gap 2300 - 1400 JSB 15.89 2.35, .047 spring
1-771 11-775 21-782 31-768
2-773 12-782 22-787 32-768
3-783 13-781 23-782 33-765
4-770 14-777 24-782 34-764
5-778 15-782 25-783 35-758
6-774 16-783 26-778 36-760
7-779 17-784 27-777 37-754
8-774 18-783 28-770 38-747
9-773 19-778 29-777
10-772 20-783 30-778
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That's all I have time to test for now, but same spring, just change preload and gap. I will try one more turn out on bolt if I have the room, which will probably drop me closer to 750fps and then decide whether to clip another coil on the .047 spring and test some more. Then a quick try with the .055" spring, which I think will be too strong, and back to testing the .041 spring.
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Wow 40 shots with a 3.68% ES. So far your test 2 and 4 are very good.
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Werent you worried about velocity at a time?
Cheers
Jay
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I wanted about 22fpe or 800 fps with jsb 18.9 which disco likes , so I am working for that.
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I like test two. Thanks for posting those strings John, I'm sure it will help others tuning.
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i think i am going to try a "thru the hammer" design. and just adj the gap with the tube end cap. i have a prod hammer already. me and the mini lathe wil spend some time together soon. gotta get some stuff from mcmaster.
your strings are for sure in the acceptable zone. pretty good improvement over stock eh?? gooday
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Definitely strings 2 and 4 are very nice and very tight ES as well on only 900 psi of air.
Mike
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Yes...I'm pretty happy so far, especially since before, even with some valve, poppit, tport mods to improve airflow I still was under 20 good shots in that range before Bob came out with the SSG.
All hail Bob Sterne.
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i had to drill my prod hammer threads out to .250 to smooth it up fairly well through the center. polished it smooth. now the stock crosman spring size wont fit the guide shaft. now to enlarge and deepen the spring cavity in the rear of the hammer. and order springs. on and on and on. gotta love it. david
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I am doing the same. Going to open spring pocket in hammer .700 depth and .500 width. Open end cap .600 depth .500 width. Having bolt head turned round and recessed into hammer . Gonna try the OEM marauder hammer. Will have almost 2 inches of spring space. Cant wait to see if it all works out. Along with double tube hoping to get 40-50 good shots. Have anew barrel at Mikes (TKO22) getting his prep work and ordered a brass trigger.
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hey folks, whats up. been fiddling with the ssg . here is what i have so far. gotta get some springs.(http://i1190.photobucket.com/albums/z451/davidmccann1969/DSCN9945_zpshfun3fbg.jpg) (http://s1190.photobucket.com/user/davidmccann1969/media/DSCN9945_zpshfun3fbg.jpg.html) (http://i1190.photobucket.com/albums/z451/davidmccann1969/DSCN9948_zpsxvhphjnw.jpg) (http://s1190.photobucket.com/user/davidmccann1969/media/DSCN9948_zpsxvhphjnw.jpg.html) (http://i1190.photobucket.com/albums/z451/davidmccann1969/DSCN9947_zps3fyyp5ob.jpg) (http://s1190.photobucket.com/user/davidmccann1969/media/DSCN9947_zps3fyyp5ob.jpg.html)
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i too am pondering a new barrel. i need a 24" long to fit the prod. where to get such an animal??
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i too am pondering a new barrel. i need a 24" long to fit the prod. where to get such an animal??
David
You can get a Mrod 20 inch barrel from crosman for a reasonable price in 177 or 22 cal but I still believe the 22 barrels are hit or miss as far as accuracy is concerned. The Prod and Mrod breeches are the same in 177 and 22 as far as I know, but you could possibly make a disco barrel fit in the Prod as well since they all are 7/16" OD and just the transfer port is slightly different between the disco and Prod as well as the bolt probe sealing method for the barrels. I do know a 22 cal 24 inch disco barrel is about 21 bucks plus 4 bucks shipping from crosman if you call them by phone.
22 cal disco barrel part number is 2260SE-001
22 cal Mrod barrel is 2264-001.
The only difference is the Prod/Mrod barrels have the bolt probe o ring in the barrel and the disco has it on the bolt probe so you could cut a groove in the Prod bolt probe for a o ring to seal in the disco barrel.
Here are the links to schematics.
https://support.crosman.com/hc/en-us/articles/203549550-BP2264S-Owner-s-Manual-EVP-2013-
https://support.crosman.com/hc/en-us/articles/203544750-BP9M22GP-Owner-s-Manual-EVP-2008-Present-
Mike
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i too am pondering a new barrel. i need a 24" long to fit the prod. where to get such an animal??
Check out Marmot Militia I know Jim makes custom length .22 barrels for prod and guaranteed to shoot great. I just don't know if he does longer than 20" though
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i too am pondering a new barrel. i need a 24" long to fit the prod. where to get such an animal??
Check out Marmot Militia I know Jim makes custom length .22 barrels for prod and guaranteed to shoot great. I just don't know if he does longer than 20" though
Dillon
Yea Jim makes very good barrel as I have a 25 cal one on the way but they are 205.00 bucks also so not a cheap barrel by no means, I was just giving him some reasonable priced options instead of spending almost as much as the gun on just a barrel.
Mike
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I got a 2260 barrel from Dennis Baker. Around 36 bucks shipped.
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i too am pondering a new barrel. i need a 24" long to fit the prod. where to get such an animal??
Check out Marmot Militia I know Jim makes custom length .22 barrels for prod and guaranteed to shoot great. I just don't know if he does longer than 20" though
Dillon
Yea Jim makes very good barrel as I have a 25 cal one on the way but they are 205.00 bucks also so not a cheap barrel by no means, I was just giving him some reasonable priced options instead of spending almost as much as the gun on just a barrel.
Mike
Very true I wasn't thinking of that. I have his .22 barrel and it's amazing. But that was because I didn't want to play barrel lottery again with the Mrod. My disco barrel is very good so if he had the means to machine his own to make it work I'd say go that route.
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thanks for the info on the barrel. i cant help but wonder why the mrod mags are different from prod? they have diff prt#. the mrod bbl stick out the back further??? i am using a 2260 bbl in a prod brch, fitted onto a disco airtube and valve. we had to grind a cutter from HHS to "scratch" the oring groove inside the bbl.i say scratch, because the cutter we ground, wound up pretty skinny out near the business end.. it screeched and chattered and carried on if you tried to force it to cut very much at all. soooooooo, it took way too long to accomplish that feat. it did work out though, and doesnt leak there at all. i hate to chuck this one because of the time spent, but the usual winning pellets dont fly consistently . it is strange but it likes AA diablo field 16gr. it will put them in a group that can be covered with a nickel at 21yrds. the rest were 1.5" groups, well, i cant really say they grouped much as it would just randomly spit them high low lft and rt. im gonna tear it back apart at the barrel- breech area, install Bob's SSG, give things a good looking over, and put it back together. maybee leave the shroud and baffles off for a minute and shoot some. does the single shot tray for the mrod fit the prod?? thank guys for all your help.TALKTOYEZ
david
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hello again, how much clearance between hammer bore and ssg guide rod, in a pass thru design??? does anyone have a recomendation? i mean the sliding area, up and down the rod.. how sloppy should it be?? my guide rod is .246. and my hammer bore is .250 it slides good, but if i put up down, or off center pressure on it it feels not as smooth in its action, as when loading it from the center area. maybee this isnt a concern. cheers
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hello again, how much clearance between hammer bore and ssg guide rod, in a pass thru design??? does anyone have a recomendation? i mean the sliding area, up and down the rod.. how sloppy should it be?? my guide rod is .246. and my hammer bore is .250 it slides good, but if i put up down, or off center pressure on it it feels not as smooth in its action, as when loading it from the center area. maybee this isnt a concern. cheers
If it were me, I would install it and test it pulling the bolt a number of times to see. Go from there.
What lube are you using on the SSG guide?
Nice work on your machining BTW.
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thank you sir. i was using a few drops of Quaker State fully synthetic motor oil. im gonna try it like it is and see.... i may polish the sliding area with 1500 first. think ill remove the shroud and try some groups today before dark, before i take the breech off. gooday
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David
I was not aware the Prod mags and Mrod mag are different and wonder if its a width thing for the ability to use longer pellets in a Mrod versus a Prod. My Mrod mags are 11/16' wide total width and the recess that slides in over the barrel is 9/16' so that a 1/16' difference that the barrel should be protruding out from the breech in the mag well area and the recess diameter is 7/16' to fit over the barrels diameter.. You can measure your Prod mag to see if it is narrower overall and in the barrel recess pocket or has a recess to fit a smaller barrel diameter. Mine is a 177 Mrod but I believe the 22s are the same size and only the 25 mags are thicker to accommodate the larger pellets in 25 cal.
Are your mags a 10 shot mag or possibly only 8 or 9 shot as that may be the difference in part numbers so a Mrod may fit as well in the prod.
I would think it possibly easier to machine an o ring groove on the Prod bolt to seal in the disco barrel instead of cutting that groove in the disco barrel to seal on the bolt probe, but then I have never tried to modify one to fit the other either so you are breaking new ground in that respect and I am sure all here would be interested in the results you come up with as I know I am indeed.
Mike
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hmm, mine measures same as yours. mine is .22- 8 shot. if yours is 10 shot, that means the "wheel" is larger dia., and that may be the prob....... anyone else know for sure???????
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i was afraid if i put the oring on the probe, it would be a constant chore changing out the worn oring, as a result of dragging in and out of the mag, maybee not. the challenge to put it inside was greater, soooo, always being one who loves challenges, i elected to go there with the oring.
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mooseslayer must be testing his toy, he didnt post yesterday. how are you doing with it mr. moose??. i ordered springs today. i found 1 in some junk boxes i was digging through. gonna put it in and try it. shooting with the shroud and baffle sys off yesterday, i cant say accuracy was leaps and bounds better.seems to like heavier pellets.and onward we go. cheers
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Are you having accuracy issues? Curious why you thought removing the shroud system would increase accuracy. As far as I know it only works if either barrel or shroud are bent or if it's clipping the baffles.
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yes, i am having some kind of accuracy issue. perhaps the pellets arent fast enough? i used the chrony the other day, and was seeing 775 ish fps. i just finished installing bobs SSG setup. maybee tomorrow afternoon i can try it again and see where we are.TALKTOYEZ
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No testing since the weekend. Busy at work and home. I am tired of wasting pellets just shooting across chrono in basement. The weather is starting to warm up here, snow is gone now, but now all-day rain (I am in Canada). I am hoping to do some actual shooting outside this weekend if the weather holds.
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yea, spring seems to have sprung here too. gotta get that tiller working... and the lawn tractor. been nice here for several days. temp in the 70's. hoping to find time this weekend to shoot some pellets. cheers
david
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i did find that the foam material i used in my baffle sys, was too soft... because when i removed the shroud with the baffle sys still inside the tube end, i looked through it with the light and saw foam sticking through my stripper holes. maybee that is why my accuracy is inconsistant ????? anyway, ive put it back together with scotchbrite material in the chamber... hope its good. using a mystery spring i found for the SSG. should have springs from mcmaster tomorrow ,.... hopefully.
TALKTOYEZ
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David
Yea the o ring could be damaged some by sliding thru the mags repeatedly as I had not thought about that since I shoot with a single shot tray all the time as I find it helps improve accuracy, not by much but I shoot FT and not by much can mean a miss or a hit at the kill zone. I doubt that the 2 extra pellet holes in the mag would cause any issue with rotation as the mag is rotated by the internal spring not by the bolt retraction causing the mag to advance so if as you say the outside dimensions are the same the Mrod mags should work in my opinion but the only way to know for sure is to try one and see.
You state you had some foam material in the baffles and now are using scotchbrite instead. The baffle system on the Prod and Mrods in designed to have open air space inside the baffles that allow the sound waves to be broken up as they pass thru the baffles at the exit of the barrel thru the four holes in the end cap on the barrel that seal to the inside of the shroud and travels thru the 4 baffles for a GEN 1 or 7 baffles for a GEN 2 gun and back all the way to the rear of the shroud at the breech. If you put any material inside the baffles or shroud behind the barrel end cap it will eventually wind up in the pellets path out of the barrel and indeed affect accuracy.
I would remove the entire shroud and baffles and swab down the inside of the shroud to clean all debris out of it and wash all the baffles in warm soapy water to remove all lead dust and lightly lube breech and barrel o ring with silicone oil and reassemble with no added foam or scotchbrite at all. While you have the shroud and baffles out clean the barrel with some pull thru patches soaked in a barrel solvent or use a barrel snake till it is bright shiny clean then pull one lightly silicone oiled patch thru it to prevent rust and see if your accuracy returns. I put a couple drops of silicone oil in the breech end of my barrels every 700 to 1000 pellets to help keep the lead fouling to a minimum.
Mike
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hey mooseslayer, check this out. im still looking for 825fps, but look what a string. im tickled pink
reated: 03-12-2016 02:55:52 PM
Description: ssg reggd 300o psi
Notes 1:
Notes 2:
Distance to Chrono (FT): 1.00
Ballistic Coefficient: 1.000
Bullet Weight (gr): 14.300
Temp: N/A
BP: N/A
Shots
# FPS FT-LBS PF
55 757 18.20 10.83
54 768 18.73 10.98
53 764 18.54 10.93
52 768 18.73 10.98
51 769 18.78 11.00
50 766 18.63 10.95
49 773 18.98 11.05
48 770 18.83 11.01
47 772 18.93 11.04
46 771 18.88 11.03
45 767 18.68 10.97
44 765 18.59 10.94
43 770 18.83 11.01
42 770 18.83 11.01
41 774 19.03 11.07
40 769 18.78 11.00
39 774 19.03 11.07
38 773 18.98 11.05
37 771 18.88 11.03
36 773 18.98 11.05
35 774 19.03 11.07
34 766 18.63 10.95
33 772 18.93 11.04
32 773 18.98 11.05
31 773 18.98 11.05
30 774 19.03 11.07
29 777 19.17 11.11
28 771 18.88 11.03
27 779 19.27 11.14
26 774 19.03 11.07
25 774 19.03 11.07
24 784 19.52 11.21
23 776 19.12 11.10
22 778 19.22 11.13
21 774 19.03 11.07
20 767 18.68 10.97
19 774 19.03 11.07
18 771 18.88 11.03
17 772 18.93 11.04
16 777 19.17 11.11
15 765 18.59 10.94
14 772 18.93 11.04
13 774 19.03 11.07
12 780 19.32 11.15
11 775 19.07 11.08
10 771 18.88 11.03
9 771 18.88 11.03
8 772 18.93 11.04
7 767 18.68 10.97
6 771 18.88 11.03
5 771 18.88 11.03
4 768 18.73 10.98
3 767 18.68 10.97
2 759 18.30 10.85
1 767 18.68 10.97
Average: 771.16
StdDev: 4.73
Min: 757
Max: 784
Spread: 27
True MV: 771.25
Shots/sec: 0.06
Group Size (IN): 0.00
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Sweet looking shot string there David.
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That is awesome! Is that got a regulator on it? What spring did you use and how long was it?
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You guys are making me want to get a Disco! Good stuff here guys. David thats a awesome string well done brother!!!
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hello buldawg. thank you for the advice on the barrel and baffle cleaning. its not quite a stock setup though, as the shroud has been made from carbon fiber tube, and the baffles are alum., and so is a simple air stripper. 3 pcs total are nestled at the front of the shroud. also made at home were the 2 parts that have the orings and keep the bbl centered inside the shroud,centering bushing on brch end and muzzle end of bbl were all made by me. the forward "centering" bushing has holes drilled to allow stripped and captured air to flow into the length of the shroud. with bobs' ssg incorp. into this gun, it is so Quiet at it current power level, the hammer hitting the poppet is louder than the muzzle report. 770 fps and near silent. never seen or heard of such in these parts.cheers
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thank you oldpro. i feel as if im not worthy of your praise. your many posts have helped me along my way . i thank you sir
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hello mooseslayer, yes sir i purchased a milo70 reg and followed instructions here on this forum and installed it myself. auto tech by trade, so fairly handy with tools n such. the spring i found was .040 wire dia .380 OD 2" long, wound up preloaded on the guide rod about 3/4" had to drill out the prod striker wider and deeper to contain the spring
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Right on were all here to help each other. post some pics of that rifle of yours.
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Thanks for the info. You are right about the big bonus with the SSG being the huge reduction in noise, especially at a little lower levels. What were your fill levels and air usage? And pictures of final product and gun would be nice.
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hello buldawg. thank you for the advice on the barrel and baffle cleaning. its not quite a stock setup though, as the shroud has been made from carbon fiber tube, and the baffles are alum., and so is a simple air stripper. 3 pcs total are nestled at the front of the shroud. also made at home were the 2 parts that have the orings and keep the bbl centered inside the shroud, brch end and end of bbl were all made by me. the forward "centering" bushing has holes drilled to allow stripped and captured air to flow into the length of the shroud. with bobs' ssg incorp. into this gun, it is so Quiet at it current power level, the hammer hitting the poppet is louder than the muzzle report. 770 fps and near silent. never seen or heard of such in these parts.cheers
That sounds really interesting, please do post pics. Did you have to use a riser?
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here ya go. ill post pic of the finished product when i tear apart to try for closer to 825fps. enjoy
(http://i1190.photobucket.com/albums/z451/davidmccann1969/DSCN9922_zpsa67uyfhg.jpg) (http://s1190.photobucket.com/user/davidmccann1969/media/DSCN9922_zpsa67uyfhg.jpg.html) (http://i1190.photobucket.com/albums/z451/davidmccann1969/DSCN9940_zpsccfe1hkl.jpg) (http://s1190.photobucket.com/user/davidmccann1969/media/DSCN9940_zpsccfe1hkl.jpg.html) (http://i1190.photobucket.com/albums/z451/davidmccann1969/DSCN9948_zpsxvhphjnw.jpg) (http://s1190.photobucket.com/user/davidmccann1969/media/DSCN9948_zpsxvhphjnw.jpg.html) (http://i1190.photobucket.com/albums/z451/davidmccann1969/DSCN9942_zpsulps6eys.jpg) (http://s1190.photobucket.com/user/davidmccann1969/media/DSCN9942_zpsulps6eys.jpg.html) (http://i1190.photobucket.com/albums/z451/davidmccann1969/DSCN9947_zps3fyyp5ob.jpg) (http://s1190.photobucket.com/user/davidmccann1969/media/DSCN9947_zps3fyyp5ob.jpg.html)
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Dang Sexy Gun!!! Now im really thinking about getting a Disco.
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no riser. drilled the disco tube and valve made homemade endcap to attach prod breech . fill to 3000 psi shot down to about 1800 psi.
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thank you sir. black walnut stump we extracted from the dirt. beautiful wood in that stump and roots. wild cherry burl tipped and capped, turned out fairly nice.all made here.
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You made that stock WoW that is a work of ART!!! Wish i had wood working skills.
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thank you sir. it represents about 50 hrs of my time on the woodwork. i enjoyed it.
http://s1190.photobucket.com/user/davidmccann1969/slideshow/ (http://s1190.photobucket.com/user/davidmccann1969/slideshow/)
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thank you sir. it represents about 50 hrs of my time on the woodwork. i enjoyed it.
http://s1190.photobucket.com/user/davidmccann1969/slideshow/ (http://s1190.photobucket.com/user/davidmccann1969/slideshow/)
You do excellent work sir. As for the shroud, breech, tube mods... that's way above my pay/skill grade but you made an incredible shooter there.
Nicely done and I really love that black walnut.
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thanks tater. 8) it just comes out. labor of love ::) ::) ::) :'( :'( :'( :'( ::) ::)
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David
Its a little to late now but you could have just used a Prod end cap and saved some time drilling for the Prod breech by only having to drill the valve or could have used a prod valve and just had to drill the tube but it looks real good and MAN that stock is awesome and actually thought it was a custom made Boyds stock.
You could make some extra cash in woodworking with art like that as its almost to nice looking to actually handle to shoot but we already know that aint going to happen. LOL
Kudos on the build and hope you get the magic number of 825 plus you are seeking as I am sure it will happen with some more time and tuning.
Mike
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thank you buldawg. we will keep poking at it. gotta make some more SSG's for our other guns. im sure my bro will want one too.
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Yep we never can be caught up with our projects since we would not know what to do with the free time or well at least have to think what we would do with it. LOL
I to was a mechanic for 45 years as well and if my hands are idle I don't know what to do with my self.
Mike
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ditto.... cheers
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Beautiful stock and nice looking compact SSG. Well done.
I think I might try to do some testing today.
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thank you mr moose. good luck today. let us know how it does fer ya.
david
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David
Does your SSG stay completely inside the rear end cap of the tube and just compress the spring on the guide so that it free floats when fired between the end cap and hammer as I cannot see where you have a hole drilled in the rear end cap for adjustment or to contain the SSG from free floating inside the tube.
If that how it works I like that idea so while it may take more to adjust for tuning once set you don't have any guide or nuts sticking out the rear of the gun. is that a 1/4 -20 bolt for the guide and if so how long is it and what spring are you using I.E. wire size and diameter and length with how much preload.
Mike
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David
Just reread the thread and saw where you stated the spring size and preload on it so would like to know the bolt size you used for the guide.
Mike
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yes sir, it is a 1/4 -20 x 3".. i had to tap a few more threads to get my preload tight enough, still needs a little more. the nut was threaded onto the bolt and turned round, instead of leaving it hex shape. my rear cap required boring inside with an end mill in the tailstock of the lathe. i bored it .030 larger than the now rounded nut, and deep enough so that a .040 "rattle" gap was created when all was assembled,rear cap in place, and uncocked. i then found a soft oring that would take up that gap ,dropped it into the rear cap, reassembled, leaving no gap, but i could push the hammer-ssg assembly rearward and compress the oring to create the small gap. the gun is soooooooo quiet. this is a reggd setup. oh yea, turning the nut round removed the material holding the nylon lock, so now its not a locknut. i used the disc sander to make 2 flats on each side of the nut and the end of the rod that hits the valve, so it could be gripped with open end wrench to tighten together. i removed all excess thread to the nut. because i had to cut a few more threads, the nut was screwed all the way to the unthreaded shoulder, so no threads for the spring to interact with , so the movement of the spring- hammer- ssg rod, all move very smoothly and consistently. applied blue loctite before final assy. hope this helps. cheers ,david
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it stays completely inside. the hammer just slides along the ssg rod, as the rod passes thru it
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The only way to do it as far as im concerned. Safe and effective.
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Yeah I'm going to try to make an internal ssg for mine as well. I bought the WAR SSG for my Mrod and being one of the first ones mine came with a strong and weak spring. I figure that weak spring should work just fine on a .177 disco.
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cool . let us know how it works
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I finally got outside and shot a string with JSB 15.9 and the .047 spring and a 770fps avg setup. I cut down my SSG rod length and 3/8 bolt to streamline a little. I got another good string with 35 shots and was nice and accurate. I want to test some more so I left the bolt longer than I need for now.
I then did test with a 2.25" long .055 spring (very strong spring) It was a bit of a bust because even with almost no preload it was extremely hard to cock. I actually used a short piece of pipe over the bolt handle to be able to do it. I did get 24 shots with an 830 average or 24.3fpe but I would have to make a big bolt handle in order to cock the gun.
(http://i1305.photobucket.com/albums/s560/mooseslayerjc/shorter%20SSG_zpsfxab1qm0.jpg)
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sorry to hear your 2nd attempt was no good. at least you dont have to tear it to pieces to tune the spring. i am wanting to see 825fps average speed from mine. its average now is 771fps. i need to milk 50fps more, somehow, without messing up my spread, or increasing my cocking force. i expect to loose a few shots in the deal. keep after it youll get it mr moose. talktoyez
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24 shots would and is sweet. Im gonna make an ssg for sure.
Cheers
Jay
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I think I can get that fpe with the .047 spring and more preload. I will give it a go next.
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David
Thanks for all the info on the contained SSG as its the details you gave that make it easy to replicate and not have to do as much trial and error in tuning of the gun. Mine has no reg so likely will not get near the shot count you are but if I can get 30 plus I will be happy and mine is 177 caliber so I am shooting for 890 to 900 FPS with JSB 10.34s.
Again thanks so much for sharing with us all.
Mike
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you sir, are very welcome. i am happy to help if i can, but i have to say big credit goes to mr sterne for sharing his knowledge on the subject. i just tried to copy his theory and design. glad it helps, cheers and good luck
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David and John,
Quick question - do either of you have any valve mods done and if not, have you considered them to reach your FPS goals?
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i did mod my disco valve. removed excess threads from inside valve, and shortened threads on front of valve. also opened up the chamber in the valve , but didnt open the throat, i mean the hole tha the vlv. stem passes thru.
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I thinned out my poppit, and took some material off corner in valve, breech, tried a bigger tport (think I put the stock one back later), made hole in gauge block bigger and drilled and tapped valve for 10-32 high tensile screws so comfortable filling past 2K. Those things got me a few more shots from stock, but the increases from the SSG dwarfed them. I was just thinking that, since the SSG is improving efficiency, maybe time to increase tport for power. I am open to suggestions...that is why I started this thread, as disco is my first PCP and I'm flying by the seat of my pants. There are so many things that can affect other things that is hard to know what combination will work best.
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yea, i know what ya mean. this gun was assembled from spare parts n such, so no starting base line to compare to , only others reports of their stock guns.
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Thanks for the info. You are right about the big bonus with the SSG being the huge reduction in noise, especially at a little lower levels. What were your fill levels and air usage? And pictures of final product and gun would be nice.
Mooseslayer !
I'm I reading right that you are filling Disco to 2300psi .. is that OK, just wondering out loud ? I was filling to about 1800-1900 on a stock gun, I will be putting in a RVA later today to play with for startersusing a Challenger back cap, which is a power adjuster.
I want 750+fps with Exacts and a good 25-30 hunting shots ... I can live with that very well.
wll2506
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There is a mod that I did, in which I took the valve and drilled and tapped the 3 holes for the retaining screws to 10/32. I then got 3 high tensile 10-32 screws and replaced the old screws with them. I will try to find the link to that mod but I believe Bob or Lloyd did tests and the shear strength was now much higher than stock and you could safely fill to much higher than 2300. It was originally a safety thing in that if I made a mistake with my 3K scuba tank and didn't shut it off at 2K psi to disco, I would still be safe.
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Here is a link to the valve screw shear test and below that is what I had in a Word doc on valve screw replacement and breech screw replacement for the disco.
http://www.gatewaytoairguns.org/GTA/index.php?topic=72672.0 (http://www.gatewaytoairguns.org/GTA/index.php?topic=72672.0)
Valve mod
The jig is made from a piece of 1" x 1.5" x 2" aluminum.... A block of steel would be better for production work.... I drilled a 3/4" hole 1.5" deep and then ran a 5/8" mill down along the bottom side and removed 0.015" to form a shallow groove (ie the hole is slightly "pear" shaped).... This forms a "V" block so that when the valve is inserted it only touches at two points.... On the opposite side is a 3/8" SHSS with the end ground flat so that it won't damage the valve when snugged up.... There are two holes drilled in the top beside the setscrew.... The front one is a #21 drill (the correct size for tapping a 10-32 thread) and the rear one is a #11 drill (just clears a 10-32 tap).... There are two brass pins, the smaller one has the end machined to 0.128" which just fits in the 8-32 tapped hole in the Disco valve.... The larger one has the end machined to nicely fit in a #21 drilled hole....
To use the jig, you slide the rear valve half in until one of the screw holes lines up with the front hole and then slide the small pin down until it locates in the 8-32 thread hole.... Then you snug up the 3/8" setscrew to hold the valve in place and pull out the pin.... If you were doing a bunch, you would set the block up in the mill, aligning the hole with the head.... but I just used a hand drill and drilled by eye, using the hole in the block to guide a #21 drill to clear out the threads in the valve.... I used a normal drill, very carefully, to just remove the threads, making sure the point didn't dig in as there isn't much meat between the bottom of the hole and the inside of the valve.... I then changed to a drill ground flat on the end to make the hole full depth with no danger of cutting through.... This operation could also have been done with a 5/32" end mill provided you stopped at the correct depth....
I loosened the setscrew, removed the valve, and the threads were evenly removed, so I turned it around and replaced it in the jig and slid it in until the newly drilled hole lined up with the rear hole in the jig.... I slid in the larger pin to locate the valve and snugged up the setscrew again....Using a 10-32 plug tap, with the hole as a guide, I tapped the hole until the tip of the tap just touched the bottom (about 3 threads).... I then changed to a bottoming tap, and got nearly 6 threads total.... I repeated this for all three holes and then ran a countersink into the top of each hole in the valve just to provide a slight relief because the thread on the screws stops a few thou from the head....
I had to shorten the 1/4" long low-profile 10-32 screws to 3/16", properly finished the ends, checked the thread in a nut (rather than risk galling the aluminum valve), and then installed them to make sure they went all the way down and that the head was seated on the flat on the valve.... Everything worked perfectly, so it was time to install it in my 9mm and give it a try.... The screws I am using are rated at 180,000 psi tensile strength, which means 108,000 psi in shear.... That will give me a 4.4:1 safety margin at 3000 psi, making the screws no longer the weak link in the Disco.... The OD of the head on the screw is a few thou smaller than the holes in the Disco tube, but the head still seats well enough to spread the load and the transfer port still lines up as good as they ever do....
Breech screw fix
I usually just end up replacing the breech screws with 6x32 button head screws... I learned with my disco which has the same tiny #4 screw that they are just way to easy to strip.... so I picked up a handful of the 6x32 button heads in stainless.... simple matter to retap the hole on the tube, don't even need to drill a fresh hole just start our tap in the hole that's there... its big enough it will recut perfect threads. You then need to hit the breech hole with a #27 drill bit and then turn the head of the screw down a touch and/or open the couterbore of the hole up a bit..... I usualy turn the screw head down to about .214 and then use a 7/32 (.2188) bit that I ground the face flat (or a 7/32 end mill if you have one lol) to counterbore the hole....
never strip a breech screw again and holds MUCH nicer...... combine that with clamping the breech for assembly/disassembly and life is a lot easier
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Here is a link to the valve screw shear test and below that is what I had in a Word doc on valve screw replacement and breech screw replacement for the disco.
http://www.gatewaytoairguns.org/GTA/index.php?topic=72672.0 (http://www.gatewaytoairguns.org/GTA/index.php?topic=72672.0)
Valve mod
The jig is made from a piece of 1" x 1.5" x 2" aluminum.... A block of steel would be better for production work.... I drilled a 3/4" hole 1.5" deep and then ran a 5/8" mill down along the bottom side and removed 0.015" to form a shallow groove (ie the hole is slightly "pear" shaped).... This forms a "V" block so that when the valve is inserted it only touches at two points.... On the opposite side is a 3/8" SHSS with the end ground flat so that it won't damage the valve when snugged up.... There are two holes drilled in the top beside the setscrew.... The front one is a #21 drill (the correct size for tapping a 10-32 thread) and the rear one is a #11 drill (just clears a 10-32 tap).... There are two brass pins, the smaller one has the end machined to 0.128" which just fits in the 8-32 tapped hole in the Disco valve.... The larger one has the end machined to nicely fit in a #21 drilled hole....
To use the jig, you slide the rear valve half in until one of the screw holes lines up with the front hole and then slide the small pin down until it locates in the 8-32 thread hole.... Then you snug up the 3/8" setscrew to hold the valve in place and pull out the pin.... If you were doing a bunch, you would set the block up in the mill, aligning the hole with the head.... but I just used a hand drill and drilled by eye, using the hole in the block to guide a #21 drill to clear out the threads in the valve.... I used a normal drill, very carefully, to just remove the threads, making sure the point didn't dig in as there isn't much meat between the bottom of the hole and the inside of the valve.... I then changed to a drill ground flat on the end to make the hole full depth with no danger of cutting through.... This operation could also have been done with a 5/32" end mill provided you stopped at the correct depth....
I loosened the setscrew, removed the valve, and the threads were evenly removed, so I turned it around and replaced it in the jig and slid it in until the newly drilled hole lined up with the rear hole in the jig.... I slid in the larger pin to locate the valve and snugged up the setscrew again....Using a 10-32 plug tap, with the hole as a guide, I tapped the hole until the tip of the tap just touched the bottom (about 3 threads).... I then changed to a bottoming tap, and got nearly 6 threads total.... I repeated this for all three holes and then ran a countersink into the top of each hole in the valve just to provide a slight relief because the thread on the screws stops a few thou from the head....
I had to shorten the 1/4" long low-profile 10-32 screws to 3/16", properly finished the ends, checked the thread in a nut (rather than risk galling the aluminum valve), and then installed them to make sure they went all the way down and that the head was seated on the flat on the valve.... Everything worked perfectly, so it was time to install it in my 9mm and give it a try.... The screws I am using are rated at 180,000 psi tensile strength, which means 108,000 psi in shear.... That will give me a 4.4:1 safety margin at 3000 psi, making the screws no longer the weak link in the Disco.... The OD of the head on the screw is a few thou smaller than the holes in the Disco tube, but the head still seats well enough to spread the load and the transfer port still lines up as good as they ever do....
Breech screw fix
I usually just end up replacing the breech screws with 6x32 button head screws... I learned with my disco which has the same tiny #4 screw that they are just way to easy to strip.... so I picked up a handful of the 6x32 button heads in stainless.... simple matter to retap the hole on the tube, don't even need to drill a fresh hole just start our tap in the hole that's there... its big enough it will recut perfect threads. You then need to hit the breech hole with a #27 drill bit and then turn the head of the screw down a touch and/or open the couterbore of the hole up a bit..... I usualy turn the screw head down to about .214 and then use a 7/32 (.2188) bit that I ground the face flat (or a 7/32 end mill if you have one lol) to counterbore the hole....
never strip a breech screw again and holds MUCH nicer...... combine that with clamping the breech for assembly/disassembly and life is a lot easier
Great info, thank you very much
wll
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I thinned out my poppit, and took some material off corner in valve, breech, tried a bigger tport (think I put the stock one back later), made hole in gauge block bigger and drilled and tapped valve for 10-32 high tensile screws so comfortable filling past 2K. Those things got me a few more shots from stock, but the increases from the SSG dwarfed them. I was just thinking that, since the SSG is improving efficiency, maybe time to increase tport for power. I am open to suggestions...that is why I started this thread, as disco is my first PCP and I'm flying by the seat of my pants. There are so many things that can affect other things that is hard to know what combination will work best.
I'm a newb with the gun myself and haven't even chronny tested mine yet.
I would think flow mods would allow you get better performance at lower PSI and therefore lower hammer spring pressure in your SSG.
I have been planning to angle drill the exhaust port and blending that turn a bit, using a Prod gauge plug and gauge ( from Travis ) and going from there. One thing at a time though. I want to get the SSG completed and start testing it first, then install a modified valve and test again.
Still haven't had time to do squat.
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time is that valuable commodity no one seems to have enough of. sometimes im just lazy......... talktoyez
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Are valve mods strictly for increase in fps or do they help with efficiency? My disco is in .177 and have no issues with power for my heavy pellets. I plan on making an SSG once I get my prod hammer and endcap from discosrus and hope to make a clone of my Mrod SSG for the disco being able to control gap with an adjuster. We'll see how it turns all out
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most folks mod valves for more power. i know thats why i do it. usually doesnt help efficiency, unless some magic happens.
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Time to start one. I have been working on an SSG for my .22 disco. When I first got it I was disappointed with the 14 or so usable shots. In the past I have tried with my diy PA and some porting of valve, thinning poppit, and different tport sizes to try to get over 20 shots with jsb 15.9 at 800-850fps. I am a rookie at this and nobody up in my area that I know doing this stuff so flying by the seat of my pants.This is just what I want for hunting small game. I have come close to it. I had drilled out my endcap long ago and threaded so I could change springs on the fly so Bob's first SSG was easy to adapt to. I tried Bob's first SSG 3inch and used my existing .040" thick springs in varying lengths but power dropped was first in mid 600fps. I made a new longer one and a couple of springs and even welded a 3/8 nut to the back of my endcap to be able to use the longer ssg before coil bind. I got back to 750fps and got a ton more shots. I am waiting on order for 10" long .312 springs n .037, .041. .047 and .055 for testing.
I'm using a Challenger RVA cap so I just cut off about 3/8"+ of coils and adjusted till I got 750fps with Exact 15.9 gr pells. When I first shot her after cutting coils she was getting 705fps with that same pellets.
So after I turned the adjustment knob I brought her up to 750fps, have not tested but hope I can get a good 30+ shots at this power setting.... good enough for a good mornings pest control hunt to 60 yds as it has well over 12 fpe at that range, so I'm happy.
Not trying to turn this gun into a 338 Lapua, just a manageable, doable pest gun at reasonable ranges with out loosing power after 15-20 shots or so !
wll
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A good rule of thumb for the transfer port size for best power and efficiency balance is for the transfer port to be 75% of the bore diameter.
A 177 caliber should have a TP port hole of .133" and can go as big as .140" without pellet loading issues.
A 22 caliber should have a TP port hole of .165" and can go as big as .1875" without pellet loading issues.
A 25 caliber Should have a TP port hole of .1875" and can go as big as .200" without pellet loading issues
The above are intended for use with round nose pellets as pointed or wadcutter will have some issue loading in the bigger port diameters but I have found that loading with the barrel pointing downward while gently shaking the gun to allow the pellet to slide past the port on its own works quite well with the max size ports.
Mike
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Thanks for the confirmation of its mainly a power thing and not a efficient thing. Also thanks for letting me know bout the tp sizes. Since I have a .177 and the stock TP size of a disco is .140 it looks like I'm goin to leave the gun stock besides making an SSG.
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Some clarification on the TP port sizes in that the only issue with pellet loading as far as transfer port hole size is if the barrel port was drilled out to the max sizes. The transfer port itself will not affect pellet loading if it is over the max size unless it is the actual entry hole diameter of barrel port so you can go bigger with the port or tubing or what ever is used as the seal between the tube and barrel.
Just limit the barrel port size to those listed above as it will be the choke point so a bigger port seal tube will only create a choke point in the air flows path. It can at times be somewhat beneficial to reduce the sealing tube/port size to create a venturi effect such as in a carburetor which tends to increase the air flow velocity thru the venturi but the gains may only be marginal if at all.
Test with a smaller port as you can always go bigger easier than go back smaller.
Mike
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Thanks for the confirmation of its mainly a power thing and not a efficient thing. Also thanks for letting me know bout the tp sizes. Since I have a .177 and the stock TP size of a disco is .140 it looks like I'm goin to leave the gun stock besides making an SSG.
Mike's information is correct and the same I've seen prior on the TP ports and barrel port with similar concerns for barrel port size working on pumpers. That's where I started with valve mods on air guns. Pumpers are different and I understand that but some of the modifications done to improve airflow are the same. You can also leave the port sizes stock but still pickup some flow and add power. Whenever you do that, you use more air one way or another.
In regards to efficiency, I was talking in terms of efficient air flow and reducing turbulence. I was looking at leaving the TP port and barrel port close to stock and improving the flow through those holes by improving airflow upstream. Hence the angle drilling of the exhaust port and working / blending the sharp turn in the roof of the port and reducing the poppet stem behind the head and/or enlarging the throat.
Like you, I'm going to start out stock and put the SSG on it and go from there. I'm running .22 caliber though, so I have a bit more room for power improvement. I don't however want to go hogging out the passages, making a noisy, air wasting gun.
In your case, with the .177 caliber, I think you are making the right choice, particularly if you don't have goals of making much more power and just want more shots and flatter ES.
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Thanks for the confirmation of its mainly a power thing and not a efficient thing. Also thanks for letting me know bout the tp sizes. Since I have a .177 and the stock TP size of a disco is .140 it looks like I'm goin to leave the gun stock besides making an SSG.
Mike's information is correct and the same I've seen prior on the TP ports and barrel port with similar concerns for barrel port size working on pumpers. That's where I started with valve mods on air guns. Pumpers are different and I understand that but some of the modifications done to improve airflow are the same. You can also leave the port sizes stock but still pickup some flow and add power. Whenever you do that, you use more air one way or another.
In regards to efficiency, I was talking in terms of efficient air flow and reducing turbulence. I was looking at leaving the TP port and barrel port close to stock and improving the flow through those holes by improving airflow upstream. Hence the angle drilling of the exhaust port and working / blending the sharp turn in the roof of the port and reducing the poppet stem behind the head and/or enlarging the throat.
Like you, I'm going to start out stock and put the SSG on it and go from there. I'm running .22 caliber though, so I have a bit more room for power improvement. I don't however want to go hogging out the passages, making a noisy, air wasting gun.
In your case, with the .177 caliber, I think you are making the right choice, particularly if you don't have goals of making much more power and just want more shots and flatter ES.
Yeah my disco is tuned shooting AA 10.34 around 20fpe for 16 shots with an ES of 2% which is untouched from mac1. If anything I would want to dial it back to 880-900fps instead of around 935-940 but am wanting to wait to tune until i get an SSG figured out. If I want more power I have a .22 and .25 marauder both with plenty of mods for power so I don't need more power out of my disco.
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Dillon
Just an FYI on the JSB/AA 10.34s shooting them at the 935/940 fps you state you are getting now is to fast for the best accuracy from them, if you indeed slow them down to 890/900 fps you will a see a marked improvement in accuracy with them.
I shoot field target with a 177 Mrod and used to shoot them at 920 fps until one of the far more experienced club members told me if I slowed them down to 890/900 fps I would improve my score by a good bit and that's what I did and scored my best match since the year and a half I had been shooting FT.
I also got the added benefit of 10 more shots per fill so I believe if you slow them down to the 890/900 you are wanting to get you will likely get 20 plus shot per fill and increase your accuracy and groups as well. It worked for me and you can always turn it back up. The SSG will just improve the tune you already have in it.
Mike
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hello here, hope everyone is well. we all have the crud here. did muster courage to shoot a string today. diff ammo this time check this out. remember, only 104cc res. i did delete 3 errors that fired but werent read.
Created: 03-15-2016 06:14:06 PM
Description: 3000psi jsb 18.3 jumbo heavy end 900psi reggd disco
Notes 1:
Notes 2:
Distance to Chrono (FT): 1.00
Ballistic Coefficient: 1.000
Bullet Weight (gr): 18.130
Temp: N/A
BP: N/A
Shots
# FPS FT-LBS PF
79 669 18.02 12.13
78 671 18.13 12.17
77 681 18.67 12.35
76 681 18.67 12.35
75 676 18.40 12.26
74 680 18.62 12.33
73 679 18.56 12.31
72 676 18.40 12.26
71 681 18.67 12.35
70 684 18.84 12.40
69 682 18.73 12.36
68 678 18.51 12.29
67 690 19.17 12.51
66 683 18.78 12.38
65 687 19.00 12.46
64 680 18.62 12.33
63 688 19.06 12.47
62 ERROR 3
61 681 18.67 12.35
60 685 18.89 12.42
59 690 19.17 12.51
58 688 19.06 12.47
57 691 19.23 12.53
56 685 18.89 12.42
55 690 19.17 12.51
54 685 18.89 12.42
53 679 18.56 12.31
52 680 18.62 12.33
51 683 18.78 12.38
50 687 19.00 12.46
49 689 19.11 12.49
48 689 19.11 12.49
47 696 19.50 12.62
46 689 19.11 12.49
45 689 19.11 12.49
44 692 19.28 12.55
43 688 19.06 12.47
42 686 18.95 12.44
41 689 19.11 12.49
40 690 19.17 12.51
39 690 19.17 12.51
38 693 19.34 12.56
37 695 19.45 12.60
36 694 19.39 12.58
35 692 19.28 12.55
34 685 18.89 12.42
33 687 19.00 12.46
32 686 18.95 12.44
31 685 18.89 12.42
30 685 18.89 12.42
29 687 19.00 12.46
28 687 19.00 12.46
27 687 19.00 12.46
26 696 19.50 12.62
25 690 19.17 12.51
24 690 19.17 12.51
23 689 19.11 12.49
22 687 19.00 12.46
21 694 19.39 12.58
20 690 19.17 12.51
19 694 19.39 12.58
18 694 19.39 12.58
17 683 18.78 12.38
16 686 18.95 12.44
15 688 19.06 12.47
14 682 18.73 12.36
13 691 19.23 12.53
12 683 18.78 12.38
11 682 18.73 12.36
10 685 18.89 12.42
9 686 18.95 12.44
8 682 18.73 12.36
7 684 18.84 12.40
6 678 18.51 12.29
5 681 18.67 12.35
4 674 18.29 12.22
3 678 18.51 12.29
2 682 18.73 12.36
1 685 18.89 12.42
Average: 685.56
StdDev: 5.60
Min: 669
Max: 696
Spread: 27
True MV: 685.64
Shots/sec: 0.03
Group Size (IN): 0.00
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Thanks Mike that's what I was hoping for not that it isn't accurate now but alittle improvement is always welcome. I've noticed my jsbs 18.13 for the Mrod prefer under 900 as well even though there still very accurate above.
David Mccann that is an amazing shot string very impressive.
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thank you sir, lucky i guess. i sure as heck am no genius. id rather be lucky than good. if your good, people expect more consistency from you. all the time. lol cheers
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Thanks Mike that's what I was hoping for not that it isn't accurate now but alittle improvement is always welcome. I've noticed my jsbs 18.13 for the Mrod prefer under 900 as well even though there still very accurate above.
David Mccann that is an amazing shot string very impressive.
Dillon
The 10.34s and 18.13s are two different shape pellets with different BCs so they will respond somewhat different at different velocities. The 10,34s are a dumbbell shape and therefore have slightly less drag in flight and the higher velocity will tend to destabilize them more so than the Diabolo shape of the 18.13s since those have more drag on the flared skirt which help to stabilize them at the higher velocities. It does not really make a significant difference until you get up in the transonic regions of 960/970 fps plus ranges but it does have some effect and more so on the 10.34s than 18.13s.
Mike
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David lucky or not either way that gun you built is pretty great and makes others like me want to do stuff like you have to have so many shots from that small of a res it's very impressive.
Mike thanks for clarifying I never really thought that the different shapes would make much of a difference but I'm very appreciative for that knowledge. So I will definitely be shooting for a tune around the 17-18 fpe range with them.
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Dillon
My Mrod FT gun is tuned for 18.6 fpe or right at 890 to 900 fps with the 10.34s and is a 1/2" group gun at 50 yards if I do my part as it is far more accurate them I am.
I prefer 15,89s in my 22s but right now it because I have 5000 of them to shoot up and then will be buying 18.13s or even the 25 grainers for my Hatsan AT44 that shoots the 25 grainer at 850 fps for a whopping 41 fpe at 35 full power shots in factory stock form.
Mike
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hello here, hope everyone is well. we all have the crud here. did muster courage to shoot a string today. diff ammo this time check this out. remember, only 104cc res. i did delete 3 errors that fired but werent read.
Created: 03-15-2016 06:14:06 PM
Description: 3000psi jsb 18.3 jumbo heavy end 900psi reggd disco
Notes 1:
Notes 2:
Distance to Chrono (FT): 1.00
Ballistic Coefficient: 1.000
Bullet Weight (gr): 18.130
Temp: N/A
BP: N/A
Shots
# FPS FT-LBS PF
79 669 18.02 12.13
78 671 18.13 12.17
77 681 18.67 12.35
76 681 18.67 12.35
75 676 18.40 12.26
74 680 18.62 12.33
73 679 18.56 12.31
72 676 18.40 12.26
71 681 18.67 12.35
70 684 18.84 12.40
69 682 18.73 12.36
68 678 18.51 12.29
67 690 19.17 12.51
66 683 18.78 12.38
65 687 19.00 12.46
64 680 18.62 12.33
63 688 19.06 12.47
62 ERROR 3
61 681 18.67 12.35
60 685 18.89 12.42
59 690 19.17 12.51
58 688 19.06 12.47
57 691 19.23 12.53
56 685 18.89 12.42
55 690 19.17 12.51
54 685 18.89 12.42
53 679 18.56 12.31
52 680 18.62 12.33
51 683 18.78 12.38
50 687 19.00 12.46
49 689 19.11 12.49
48 689 19.11 12.49
47 696 19.50 12.62
46 689 19.11 12.49
45 689 19.11 12.49
44 692 19.28 12.55
43 688 19.06 12.47
42 686 18.95 12.44
41 689 19.11 12.49
40 690 19.17 12.51
39 690 19.17 12.51
38 693 19.34 12.56
37 695 19.45 12.60
36 694 19.39 12.58
35 692 19.28 12.55
34 685 18.89 12.42
33 687 19.00 12.46
32 686 18.95 12.44
31 685 18.89 12.42
30 685 18.89 12.42
29 687 19.00 12.46
28 687 19.00 12.46
27 687 19.00 12.46
26 696 19.50 12.62
25 690 19.17 12.51
24 690 19.17 12.51
23 689 19.11 12.49
22 687 19.00 12.46
21 694 19.39 12.58
20 690 19.17 12.51
19 694 19.39 12.58
18 694 19.39 12.58
17 683 18.78 12.38
16 686 18.95 12.44
15 688 19.06 12.47
14 682 18.73 12.36
13 691 19.23 12.53
12 683 18.78 12.38
11 682 18.73 12.36
10 685 18.89 12.42
9 686 18.95 12.44
8 682 18.73 12.36
7 684 18.84 12.40
6 678 18.51 12.29
5 681 18.67 12.35
4 674 18.29 12.22
3 678 18.51 12.29
2 682 18.73 12.36
1 685 18.89 12.42
Average: 685.56
StdDev: 5.60
Min: 669
Max: 696
Spread: 27
True MV: 685.64
Shots/sec: 0.03
Group Size (IN): 0.00
That bust be a modded disco to fill to 3000psi, or you are braver than me.
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yes sir modded screws
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David
You are using grade 8 10-32 screw in the valve correct to be safe to 3000 psi. I am going the same route with my modded disco tubed, prod trigger, challenger hammer and RVA setup with a daisy Avanti 20 inch LW barrel 177 caliber and 1399 stocked FT gun I am working one now.
Hoping for 60 plus shot at 900 fps with JSB 10.34s to be able to shoot an entire match on one fill.
Mike
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18-8 stainless steel 8-32
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Disregard
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I found the link to rsterne recommended 10-32 bolts from Mcmaster Carr ..
http://www.mcmaster.com/#91306a352/=vhazyb (http://www.mcmaster.com/#91306a352/=vhazyb)
I measured the depth of my existing hole set the stop on my drill press to only drill the same depth as the existing valve screw hole. I could actually see where the tip of the drill just scored the bottom of the hole. I then took another drill I ground flat to finish the last bit. I also used the drill press to start the tap perfectly straight and then finished by hand with a bottoming tap. You can feel when you hit bottom. i think I got 5 full turns on the screw. I had the 3 screws given to me from another member because they wouldn't ship to Canada.
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on my 3000psi fill disco I used m5 valve screws and also drilled the breech ,tube and rear of the valve in the 22xx forward breech position with a m4
the next one I do i'll make a new valve front so the trigger frame front screw screws into the valve like a 13xx and will also fit a grubscrew through the tube from the top in the same location extra to the std fixing locations
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18-8 stainless steel 8-32
David
Do those screws have the .3125" head and are they button head, low profile or allen head screws. Got a link to the source and specs of the screws.
Mike
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I will post a link. I had to shorten them a little and reduce head dia a bit , so they would fit the disco tubes holes. Think they were from McMaster Carr. Post later.. cheers
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David
Sounds good and no rush as if you just have the part number I cam look them up as I have an account with them and they ship to me from Atlanta only two hours away so I have driven to get stuff if I am going to be in the area for other reasons.
No rush
Mike
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http://www.mcmaster.com/#91772a189/=11m2xf2 (http://www.mcmaster.com/#91772a189/=11m2xf2) http://www.mcmaster.com/#91400a189/=11m30ku (http://www.mcmaster.com/#91400a189/=11m30ku)
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ive got 90 of the stainless ones. ill drop some in the mail to ya. how bout that??
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David
PM sent with shipping address and very much appreciated for you generosity.
Mike
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http://www.mcmaster.com/#91772a189/=11m2xf2 (http://www.mcmaster.com/#91772a189/=11m2xf2) http://www.mcmaster.com/#91400a189/=11m30ku (http://www.mcmaster.com/#91400a189/=11m30ku)
I bought some the same mil spec ones just last week from McMaster -Carr. I won't be using pressure past 2200, just putting them in for insurance.
wll
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http://www.mcmaster.com/#91772a189/=11m2xf2 (http://www.mcmaster.com/#91772a189/=11m2xf2) http://www.mcmaster.com/#91400a189/=11m30ku (http://www.mcmaster.com/#91400a189/=11m30ku)
I bought some the same mil spec ones just last week from McMaster -Carr I won't be using pressure past 2200, just putting them in for insurance.
wll
So these are the same threads as the stock bolts right? Just a drop in? I wouldn't do more than a 2200psi fill either and would be nice if it's the same threads so don't need to drill and tap.
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should fit, may have to remove a thread so they will screw down to the head... same thread size and pitch
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should fit, may have to remove a thread so they will screw down to the head... same thread size and pitch
Perfect thank you sir for the confirmation
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http://www.mcmaster.com/#91772a189/=11m2xf2 (http://www.mcmaster.com/#91772a189/=11m2xf2) http://www.mcmaster.com/#91400a189/=11m30ku (http://www.mcmaster.com/#91400a189/=11m30ku)
I bought some the same mil spec ones just last week from McMaster -Carr I won't be using pressure past 2200, just putting them in for insurance.
wll
So these are the same threads as the stock bolts right? Just a drop in? I wouldn't do more than a 2200psi fill either and would be nice if it's the same threads so don't need to drill and tap.
Same threads but a bit stronger ... I would not push the envelope. I have some others coming from Magnum-Air that are supposed to be good to 2500psi ... but I would not push that either. The only really safe screw if you are going around the 2300+ area is using 10x32. I really trust Bob and Lloyd in the testing they do, IMHO there is no one better.
I would love to do it, but I really messed up one valve housing and don't want to mess up any more. I'm ~comfortable with the replacement screws at the psi I tend to use. I have said 2200 is my goal, but in reality it is more like 2000 to 2100.
When I get these screws in and change them, if I can get a good 25+ shots using JSB 15.9 at the 750fps mark .... that it for me ... that's what that gun will do, I'm not going to make an elephant gun out of a mouse gun ! I did the same thing with my QB's, set perimeters and that was it. My hottest QB just got a couple shims (.120 worth) removed because of poor shot count, and if shot count increase and she looses some speed .... that's just hard cheese and I'll live with it. The regulator is set to 1350 outgoing, and I'm not going any higher than that.
wll2506
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i will give this gun the 10-32 mod at the next teardown. ive emptied the tube and removed the screws one at a time and inspected them and their holes and the tube. all look like they did when i put it together. screws are straight and threaded holes dont appear to be stressed sideways. ill do the mod anyway.
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Man alive, it sure sounds like those stock screws are #$^&@. Have not heard of anyone getting hurt, but lots of folks are not happy about them.
wll2506
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i will give this gun the 10-32 mod at the next teardown. ive emptied the tube and removed the screws one at a time and inspected them and their holes and the tube. all look like they did when i put it together. screws are straight and threaded holes dont appear to be stressed sideways. ill do the mod anyway.
David, how much shooting did you do with 3000psi in the gun, did you use it a few months or ? just want to get an idea. I just wish I could drill straight, and i was using a jig !
wll2506
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i have filled and shot it down 6 times since the build. near 350 shots i would guess. the last 2 fills after the ssg installed, gave me 80 shots from 3000 down to 900 psi...jsb 18.13,.... amazed......... 104cc res
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the valve in this disco also has the 2 forward breech screws thru the tube and into the valve.... they are 4-40.. as it has the prod breech fitted.
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David
Do the two prod breech screws fit tight thru the holes in the tube or did you make the holes bigger than the 4-40 screws like they are in the Prod and Mrod tubes. While they will add some strength to the retention of the valve in the tube just by the fact that there is two additional screws there. Unless they fit the holes in the tube tight like the heads of the retention screws do it is likely only their clamp load of the valve in the tube that is of any benefit but any extra is better than none at all.
I like the idea of the Prod breech on the disco tube, so did you use a prod valve so it already had the breech holes in the valve or did you drill a disco valve for the breech holes as well as the tube.
Mike
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yes, used a disco valve. holes drilled and tapped thru the tube and vlv. at same time... so tube has threads too.easy to mess this up, so use caution with that $45 prod breech as you start relocating the forward holes further forward, so the breech screws will hit the meat of the front of the valve. be really easy to drill crooked or break out the side. i was nervous.
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Yes that's what I was wondering and might be as easy and less nerve racking to just get the prod valve and only have to drill tube. At least with the tube and valve threaded it adds a good bit more support for the valve at the 3000 psi.
Did you buy the breech from crosman direct or aftermarket vendor as I was just curious if that's the price from crosman for the breech. I am thinking of doing the same thing so I can have the barrel shrouded like the prod and mrods are for noise reduction.
Mike
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stock crosman breech. the t port on the prod vlv. doesnt match the disco tube. i think i am correct on this. someone else may confirm?
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David
If the prod valve port does not match the disco tube then how does the prod breech T port line up to the disco valve port or did you have to adjust the placement of the breech on the tube to line up with the T port hole in the disco tube so that you had to drill all 4 breech screw holes in the tube and if so were the holes moved forward or backward on the tube and in the valve. If moved forward then do the two rear breech screws still thread into the end cap or just the tube in the hammer and spring pocket of the tube. I looked at the schematic of a prod and it shows the T port ahead of the valve retention screws versus the disco valves T port being inline with the valve retention screws. So it appears you would have to adjust the breech rearward to line up the T ports of the breech and tube/valve in a disco.
The rear two breech screws in the prod thread into the end cap directly inline with the single disco breech screw hole of a disco end cap as I have several 2240 with a prod end cap that I had to drill and tap the one hole to mount a rear breech screw to from the 2240s to have a prod RVA adjuster.
If the two rear screws are in the end cap for the prod breech I would think the T port is at the same location as a disco valve is but like you am not 100% sure. Very good point you brought up and I just assumed they were the same but according to the schematics they are different.
Anyone out there have one of each they can compare.
Mike
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you are correct. the rear screws secure into the rear cap. i positioned the prod brch using the t port "sleeve" to align with disco vlv., then marked and drilled rear holes into my custom rear cap. the forward screws landed in the threaded area of the disco vlv., and would have broken into the threaded cavity inside the vlv., which would result in a serious leak ..those 2 holes had to be moved forward .600 to hit the "meat" of the front portion of the disco vlv... hope this helps u to understand (http://i1190.photobucket.com/albums/z451/davidmccann1969/DSCN7497_zpskoscjwcv.jpg) (http://s1190.photobucket.com/user/davidmccann1969/media/DSCN7497_zpskoscjwcv.jpg.html) (http://i1190.photobucket.com/albums/z451/davidmccann1969/DSCN7488_zpsof0aazqv.jpg) (http://s1190.photobucket.com/user/davidmccann1969/media/DSCN7488_zpsof0aazqv.jpg.html)
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bulldawg: screws are on their way to you... ;) ;) ;) ;) ;)...cheers
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David
Pictures are worth a thousand words and I can see the repositioning of the forward screws and rear screws very clearly and you indeed had some very tedious and nervous machine work with that modification and a job very well done IMO.
I may think out my plans a bit longer before tackling that much machine work as I have access to a big mill and lathe but need to get the parts in hand and measure 5 times to drill once. LOL.
Thanks for the screws and will keep you up to speed on my progress. I am in the middle of a QB build right now so got a few irons in the fire so to speak and also have the parts on their way to complete a 25 Mrod bottled custom 100 fpe gun I have been waiting on a barrel and valve for to get completed.
Mike
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yea, i know about too many irons , just finished an engine install on a isuzu rodeo, pulling a cyl head today on a corsica, and a brake job on another vehicle and a tune up on another and on it goes........ if you have access to a machine shop, youll have no trouble. i used this;: (http://i1190.photobucket.com/albums/z451/davidmccann1969/DSCN7550_zps1lw6zkpt.jpg) (http://s1190.photobucket.com/user/davidmccann1969/media/DSCN7550_zps1lw6zkpt.jpg.html)
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Just got my screws for the disco, and tried to fix the valve i though i destroyed ... well I fixed it, here is a pic... I will be using 10x32 screws after all ;- ) I'm very happy I could fix this valve body, the one hole i did not thread I threaded and the one that I though was loos and not usable was the Air hole ... so I was OK, All screws are tight :
http://s20.postimg.org/3zjlxpsal/10x32_in_Valve_smx.jpg (http://s20.postimg.org/3zjlxpsal/10x32_in_Valve_smx.jpg)
wll
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Good to hear. Peace of mind is a great thing. I still inspected my valve and my screws like Lloyd's post suggests, the next time I opened my gun up.
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Just a quick mention on the 10-32 screws and modifying for more power and pressure. I followed Bob Sterne's post on disco valve mods. He goes to .25 on the throat. I elected to go slightly less at 15/64 and quickly realized after cleaning the valve body all three of the threaded holes for the retaining screws had daylight in the bottom. Not much - just pin holes at the bottom of the bores but they were through. I plan to finish them off and go right through into the valve body when drill and tap for 10-32. Should I be concerned?
Ordering an extra valve body, Prod hammer weight, Prod gauge block, and Prod gauge today to complete the setup and build internal SSG to go with it.
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should still work fine. i believe a leak there would be minimal, and only during the fraction of a second that the shot occurs.
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how ya been mr moose?? too much going on around here, no time to play much. my belly says it is supper time. hows the temps in canada? 54* here today, a bit nippy to suite me. been making more ssg rods for the rest of the fleet. doing one for leeann's bulk co2 1760 next. we have strings from last summer, so we can compare apples and oranges when we get it tuned. looking forward to testing and tuning it.....cheers
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yea, i know about too many irons , just finished an engine install on a isuzu rodeo, pulling a cyl head today on a corsica, and a brake job on another vehicle and a tune up on another and on it goes........ if you have access to a machine shop, youll have no trouble. i used this;: (http://i1190.photobucket.com/albums/z451/davidmccann1969/DSCN7550_zps1lw6zkpt.jpg) (http://s1190.photobucket.com/user/davidmccann1969/media/DSCN7550_zps1lw6zkpt.jpg.html)
David
Yea I have access to a much larger and more stable lathe and mill to do the work on and will get there in time but like you have many iron in the fire at once as well so all good things in time.
Just trying to prioritize at this point is enough on its own and try to do what I can as I get the parts to get each project done. Plus like you working on friends, family and neighbors cars at the same time. Just never enough time in a day. LOL
Mike
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Just got my screws for the disco, and tried to fix the valve i though i destroyed ... well I fixed it, here is a pic... I will be using 10x32 screws after all ;- ) I'm very happy I could fix this valve body, the one hole i did not thread I threaded and the one that I though was loos and not usable was the Air hole ... so I was OK, All screws are tight :
http://s20.postimg.org/3zjlxpsal/10x32_in_Valve_smx.jpg (http://s20.postimg.org/3zjlxpsal/10x32_in_Valve_smx.jpg)
wll
Will
Glad you found you could salvage the valve and have the satisfaction of completing the job successfully. Well done.
Mike
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Just a quick mention on the 10-32 screws and modifying for more power and pressure. I followed Bob Sterne's post on disco valve mods. He goes to .25 on the throat. I elected to go slightly less at 15/64 and quickly realized after cleaning the valve body all three of the threaded holes for the retaining screws had daylight in the bottom. Not much - just pin holes at the bottom of the bores but they were through. I plan to finish them off and go right through into the valve body when drill and tap for 10-32. Should I be concerned?
Ordering an extra valve body, Prod hammer weight, Prod gauge block, and Prod gauge today to complete the setup and build internal SSG to go with it.
Steve
You should be fine if the heads are snug on the side of the valve and for some extra sealing insurance you can apply some pink Loctite to the screw threads which will seal any gaps in the screw to the threads of the valve but still be easily removed as it is a the lowest strength of Loctite and used for very small screw like 4-40 and below so a 10-32 will come loose with very little effort when desired but will not loosen on its own and the Loctite will seal any air leak past the screws threads completely.
Mike
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My first attempt at internal ssg worked for a while then started to get hard to cock and then not cock at all. I have 1/4-20 bolt going thru hammer with the front of hammer with round pocket and bolt head recessed into it. Dont know what the spring is i picked it up at hardware store. Nylon locknut holding it all together. I cant figure out what is binding. When I take it all apart everything seems smooth. My Disco has a double tube and I would say the ssg theory does work. I pumped gun to 2300 (upgraded valve screws) and started shooting over chrony. First shot was 761 and started slowly climbing and by shot 53 was up to 802 when it wouldnt cock anymore. Still had probably 1600 psi still in gun. I think the sound is different also. Not as loud. 14.3 gr Crosman pellets btw.
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When I went to a heavy spring I noticed a bind. I saw a mark on the hammer from one of the slots so i got my dremel out and chamfered them and then polished both the hammer and the chamber to 1500grit. It is nice and smooth now. Check you hammer to see if any noticable marks where it could be catching.
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Just a quick mention on the 10-32 screws and modifying for more power and pressure. I followed Bob Sterne's post on disco valve mods. He goes to .25 on the throat. I elected to go slightly less at 15/64 and quickly realized after cleaning the valve body all three of the threaded holes for the retaining screws had daylight in the bottom. Not much - just pin holes at the bottom of the bores but they were through. I plan to finish them off and go right through into the valve body when drill and tap for 10-32. Should I be concerned?
Ordering an extra valve body, Prod hammer weight, Prod gauge block, and Prod gauge today to complete the setup and build internal SSG to go with it.
Steve
You should be fine if the heads are snug on the side of the valve and for some extra sealing insurance you can apply some pink Loctite to the screw threads which will seal any gaps in the screw to the threads of the valve but still be easily removed as it is a the lowest strength of Loctite and used for very small screw like 4-40 and below so a 10-32 will come loose with very little effort when desired but will not loosen on its own and the Loctite will seal any air leak past the screws threads completely.
Mike
Thanks for the tip Mike. I went with 222 formula which is low strength violet. Is that what you meant? I have 224 blue at home and haven't had much difficulty with removing fasteners using that but this does sound like a better solution. All parts are ordered today. The low 10-32 x 1/4 SHCS, 4K PSI gauge, 1/8NPT high pressure stainless adapter from McMaster and other parts from Crosman including another hammer and valve assembly. The only thing I lack for my internal SSG build will be springs and a bolt which I will probably source locally from the hardware store. I actually do not plan to pressurize the gun much past 2000 psi but want the added safety margin.
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Just a quick mention on the 10-32 screws and modifying for more power and pressure. I followed Bob Sterne's post on disco valve mods. He goes to .25 on the throat. I elected to go slightly less at 15/64 and quickly realized after cleaning the valve body all three of the threaded holes for the retaining screws had daylight in the bottom. Not much - just pin holes at the bottom of the bores but they were through. I plan to finish them off and go right through into the valve body when drill and tap for 10-32. Should I be concerned?
Ordering an extra valve body, Prod hammer weight, Prod gauge block, and Prod gauge today to complete the setup and build internal SSG to go with it.
Steve
You should be fine if the heads are snug on the side of the valve and for some extra sealing insurance you can apply some pink Loctite to the screw threads which will seal any gaps in the screw to the threads of the valve but still be easily removed as it is a the lowest strength of Loctite and used for very small screw like 4-40 and below so a 10-32 will come loose with very little effort when desired but will not loosen on its own and the Loctite will seal any air leak past the screws threads completely.
Mike
Thanks for the tip Mike. I went with 222 formula which is low strength violet. Is that what you meant? I have 224 blue at home and haven't had much difficulty with removing fasteners using that but this does sound like a better solution. All parts are ordered today. The low 10-32 x 1/4 SHCS, 4K PSI gauge, 1/8NPT high pressure stainless adapter from McMaster and other parts from Crosman including another hammer and valve assembly. The only thing I lack for my internal SSG build will be springs and a bolt which I will probably source locally from the hardware store. I actually do not plan to pressurize the gun much past 2000 psi but want the added safety margin.
Steve
Yep its Loctite 222 and I am somewhat color blind as I see it as more of a pink than violet so its just a red thing I guess. The blue would work as well but it is not really necessary as there is no forces trying to cause the screws to rotate which would be the only reason to use the blue Loctite versus the violet. You sound like you are well on the way to getting it together soon.
Good luck and have fun tuning it.
Mike
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Hey all. I'm trying to figure out how to make an SSG for my Disco build. I'm wanting to get as many shots as possible with 15.9 grain JSB pellets going 600 fps for a hair under 13 fpe. Problem is, even after reading this whole thread, I can't figure out how to actually make an SSG. Could someone post a step by step tutorial on how they made theirs?
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hey folks, whats up. been fiddling with the ssg . here is what i have so far. gotta get some springs.(http://i1190.photobucket.com/albums/z451/davidmccann1969/DSCN9945_zpshfun3fbg.jpg) (http://s1190.photobucket.com/user/davidmccann1969/media/DSCN9945_zpshfun3fbg.jpg.html) (http://i1190.photobucket.com/albums/z451/davidmccann1969/DSCN9948_zpsxvhphjnw.jpg) (http://s1190.photobucket.com/user/davidmccann1969/media/DSCN9948_zpsxvhphjnw.jpg.html) (http://i1190.photobucket.com/albums/z451/davidmccann1969/DSCN9947_zps3fyyp5ob.jpg) (http://s1190.photobucket.com/user/davidmccann1969/media/DSCN9947_zps3fyyp5ob.jpg.html)
Chris
Here is a good picture of what is required to make a simple disco SSG. you need to get a 1/4' x 20 bolt about 2 1/2" long and drill the nose of the hammer out to 1/4" with a recess to allow the turned down bolt head to sit flush in the hammer face. Then use a nylock nut and washer to adjust the spring preload on the bolt to about 1/2" and install inside the spring cavity in the tube making sure the assy has about .050" or more free play with the hammer at the uncocked position so there is no tension on the hammer at rest. You may have to shorten the threaded end of the bolt to gain this clearance. That's it for a simple SSG that requires the end cap to be removed to adjust it or you can get more elaborate and thread the end cap for a adjustment bolt like in page one that mooseslayer shows. it all up to your imagination from here.
Hope this helps.
Or just buy one from here and drop it in and off you go.
http://www.network54.com/Forum/79574/message/1457965393/FS-+Disco+%28etc.%29+drop-in+FreeFlight+Hammer+Mod%27+and+Power+Adjuster+kit-+%2441 (http://www.network54.com/Forum/79574/message/1457965393/FS-+Disco+%28etc.%29+drop-in+FreeFlight+Hammer+Mod%27+and+Power+Adjuster+kit-+%2441)
Mike
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This really gets to the meat of the thread - thanks Mike.
In regards to the internal SSG pics above:
Why use a 1/4-20? There are a lot of ways to skin this cat.
Having a lathe and carbide tools would certainly be a huge advantage machining that hammer weight and bolt like that.
Is there an easier way using say a #10-24 x 2.5"? How would the smaller fastener work in regards to spring selection and would it require a deep counterbore like that?
It might be helpful to know:
- Stroke distance dimensions. What's the distance between the valve stem tip and the end of the tube? I can measure this tonight or tomorrow myself. This helps determine max overall length.
- What's the distance between the sear face and the tip of the valve stem? How far back to pull the hammer until gun can be cocked? This would provide the minimum section of non-thread for the bolt used and the total travel of the weight on the bolt.
- What's generally a good spring strength to use for starters?
This would provide the minimum section of non-threaded for the bolt used and the total travel of the weight on the bolt.
The above design may have been planned out but I more suspect it was shoot from the hip and use what's readily available or on-hand. Much easier to accomplish this sort of creation when you have great tools like a lathe. I am ordering a mini-lathe in the near future just for these sorts of projects and others around the house.
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Like said many ways to skin a cat. I have a WAR SSG for my Mrod and although very similar to that design it's much simpler. There's really no need for a counterbore it doesn't need to be flush with the hammer face and spring wise they typically like a longer lighter spring so it's under constant preload on the bolt. Not saying it can't work how David did it because he proved to us it does work great. I'm just saying there are many ways to do it.
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Like said many ways to skin a cat. I have a WAR SSG for my Mrod and although very similar to that design it's much simpler. There's really no need for a counterbore it doesn't need to be flush with the hammer face and spring wise they typically like a longer lighter spring so it's under constant preload on the bolt. Not saying it can't work how David did it because he proved to us it does work great. I'm just saying there are many ways to do it.
Its just like Dillon says there are many ways to make one and the bolt /guide can be whatever size you feel fits best and no need to countersink the head into the hammer either. I was just trying to show the concept of what is required to make a SSG from scratch and exactly how it is designed and constructed is entirely up to what fits your gun and desires on the capabilities of ease of adjustments and power limits. Those all are what dictate the spring size and strengths and guide size and lengths to either fit inside hammer cavity or protrude from rear cap to be externally adjustable as well as appealing to cosmetics versus function. There are many way to skin the cat in this instance so its all up to your abilities and equipment at your disposal.
Mike
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Mooseslayer: Where did you find your springs at?
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I got my springs at Trakar Springs in Ontario Canada.
http://www.trakar.com/products/compression-spring-length/?HoleDiameterMIN=0.093&HoleDiameterMAX=1.875&WireDiameterMIN=0.041&WireDiameterMAX=0.047&SpringRateMIN=0.1&SpringRateMAX=95&SolidHeightMIN=1.58&SolidHeightMAX=7.98&LengthMIN=10&LengthMAX=18&SolidLoadMIN=0&SolidLoadMAX=200&order=HoleDiameter&submitadvanced=Search (http://www.trakar.com/products/compression-spring-length/?HoleDiameterMIN=0.093&HoleDiameterMAX=1.875&WireDiameterMIN=0.041&WireDiameterMAX=0.047&SpringRateMIN=0.1&SpringRateMAX=95&SolidHeightMIN=1.58&SolidHeightMAX=7.98&LengthMIN=10&LengthMAX=18&SolidLoadMIN=0&SolidLoadMAX=200&order=HoleDiameter&submitadvanced=Search)
They were 10" lengths in .041 and .047 best for me.
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I cleaned up my SSG a bit.
This was the original...
(http://i1305.photobucket.com/albums/s560/mooseslayerjc/IMG_20160221_100829_zps6cqaiqvd.jpg)
This is it shortened and cleaned up ready for paint...
(http://i1305.photobucket.com/albums/s560/mooseslayerjc/IMG_20160402_154657_zps5g9bfgzk.jpg)
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lookin good. hows things in canada????
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Got a few days in 50's, but now snowing and wind howling . Just looked out and whiteout. No shooting for me for a bit
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Got a few days in 50's, but now snowing and wind howling . Just looked out and whiteout. No shooting for me for a bit
Same weather here in MI doesn't look like I'll be shooting much in the next couple of days either...
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Here is my string with my disco double with BNM breech and shroud. I went from .99 to 1.38 avg FPE/cuin per shot, so am happy
(http://i1039.photobucket.com/albums/a474/AndrewyChase/FFH%20installed%20041516_zpsdv2vyg1c.jpg~original)
http://i1039.photobucket.com/albums/a474/AndrewyChase/FFH%20installed%20041516_zpsdv2vyg1c.jpg~original (http://i1039.photobucket.com/albums/a474/AndrewyChase/FFH%20installed%20041516_zpsdv2vyg1c.jpg~original)
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Nice string Geoff. I need to get back and finish testing as the weather is finally getting nice here.
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Just jumping in here and showing my disco SSG results this is with an internal "cartridge" style SSG I made for the disco.. will post pics at a later date... its made so the entire spring/guide rod assy can be removed from the rear of the gun and no handtools are need to make adjustments after its installed....
basic statistics are....
Disco Double with
hogged out valve,
custom gauge block that's pretty much full diameter flow,
severely reduced transfer port at .120 ( though I may go smaller to flatten out curve a touch more...)
.039 heavier spring( I believe this is the same spring rstern recommends for over 2kpsi fills
String shot from 2000 to 1300 psi with 14.3 cphp's would get significantly more eff with 18.1's but since I shoot almost exclusively crosman pellets.....
here is the pudding
(http://i148.photobucket.com/albums/s8/michael90t/Airgun/Disco%20Double/DiscoDouble%20SSG_zpskawfyqqn.jpg)
here is the EFF calcs
(http://i148.photobucket.com/albums/s8/michael90t/Airgun/Disco%20Double/Mikes%20SSGDD_zpsx5mppxmx.jpg)
I am happy but not entirely satisfied with the center peak of the string.... I would prefer it to stay around 925 instead of peaking a few shots into the 130's.... may try to go to a .110 tp and see if that helps....
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Those are some incredibly flat shot strings - it looks like you're shooting a regulated gun! You guys are incredible!
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Those are some incredibly flat shot strings - it looks like you're shooting a regulated gun! You guys are incredible!
Geoffs shot string is so much prettyier.... lol mine peaks a little higher then Iwould like.... may throw in a .110 transfer port and see if I can flatten it out a touch more
or maybe get some 18.1 and not change anything and see where its at lol
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awesome strings guys. we had temps in the mid 70's. we camped all weekend.. lots of shooting time. very calm in the morning. no wind.. seems i have some very accurate 22xx /disco crossbreeds...dime size groups at 30 yrds..one ragged hole most of the time.. lovin it. several ssg installed into all mine except 2.. get to them soon.. very good mod that ssg. thanks bob for sharing.. cheers
david
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Got the QB bug right now but will get back to my disco tubed 22xx/ challenger/Prod franken gun in time so I am down but not out of the game by no means.
Mike
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I will be trying my hand on the ssg this weekend plan to be an internal one with an adjuster for gap on the back like my Mrods
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OK ill do it LOL. Been getting tons of emails for me to build a ssg for the disco so ok ill do it. Ive been so busy I just didnt have time but ill make time so if someone sends me their disco(has to be bone stock) Ill build them a ssg and tune it for free (you pay shipping fees.) Then ill use that info to make a bunch of them.
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Somebody needs to take this offer. If i didnt have everything to make one and if my gun wasn't tore apart for cocking issues and without a bolt for who knows how long I would send mine.
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If I could afford it, I'd buy one right now and have it shipped directly to you.
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PM sent. :-)
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PM accepted. We have our volunteer. ;D
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Blindfold? Cigarette?
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LOL youll be ok ;D
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And here we sit, with bated breath...
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10 days at tops. I have every spring, bolt, washer etc. I need right here in the shop. Lathe , mill chronograph you name it I got it. Its all about time and how much I can drop on this project. I have done several SSG already for mrod-prod-hatsan-2240 so it shouldnt be much of a problem.
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I thank you, my gun thanks you, my friends thank you. The squirrels... not real happy...
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Eager with anticipation is all I will say.
Mike
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this is too cool.... rain today work work work....cheers . david
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So tonight I drilled out the threads on my prod hammer 1/4" and the spring cavity to 3/8". Have a rough design together but cant test it as im waiting for a new bolt but looks very promising. Wondering what the length of the spring and bolt people are using for internal designs.
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Prod trigger assy from crosman is only 36.50 and Mrod trigger assy is only 48.93 with 4 buck flat rate shipping for both so IMO they are not pricey at all for what you get as I am building a disco tubed, 3000 psi, challenger hammer,spring and RVA, Prod triggered, 1399 stocked, steel breeched, daisy Avanti 20 inch LW barreled, FT gun right now and have less that the price of a new disco in it so far and fully expect it to shoot circles around any disco as well as get twice the shot count.
Mike
Hey Mike, how much did the Avanti barrel run?
Joe
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Joe
I rebuilt a 853 Avanti for a friend that had a busted pot metal valve housing and it comes as the barrel, valve assy and housing as a unit for 65 bucks from daisy. So I pressed the old barrel out of the cracked housing and had to machine off the reduced leade spigot that presses into the Avanti housing to have a flat end just like the breech end of a crosman barrel since its 7/16" diameter just like a crosman barrel is and 20 inches long.
Then I just located the transfer port hole position in the barrel by inserting into a steel crosman breech and drilled out the port to .140" and drilled out the leade to fit the pellets and one Avanti /Crosman barrel is born.
So I guess you could say they are 65 bucks from daisy with valve and housing that are non essential parts.
Mine was free as part of the rebuild deal.
Mike
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Nice Mike and thanks for all the info. I might have to go that route for a .177 build I'm planning.
Joe
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10 days at tops. I have every spring, bolt, washer etc. I need right here in the shop. Lathe , mill chronograph you name it I got it. Its all about time and how much I can drop on this project. I have done several SSG already for mrod-prod-hatsan-2240 so it shouldnt be much of a problem.
EXCELLENT I'll be one of the first in line to order one.
Can't use the external style one I made on my setup without clearancing my pretty Boyds stock. A lot.
I'll continue to follow this thread to see how you're doing with it and please let us know when you have them on your site and available.
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Ill post results and availability right here in this thread
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I'm pretty excited myself. I think my wife would shoot her disco more if it didn't take a fill after every dozen shots.
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I'm pretty excited myself. I think my wife would shoot her disco more if it didn't take a fill after every dozen shots.
Sooooo....your wife has a better gun than me.... :-[
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I'm pretty excited myself. I think my wife would shoot her disco more if it didn't take a fill after every dozen shots.
Sooooo....your wife has a better gun than me.... :-[
LOL!
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Nice Mike and thanks for all the info. I might have to go that route for a .177 build I'm planning.
Joe
Joe yea it is actually cheaper to go the daisy Avanti route than to buy a Crosman challenger LW barrel as they are 93 bucks plus 4 bucks shipping. The Avanti barrel does require some machining to work but then thats half the fun IMO.
I have been stalled on my Disco franken gun build as I got the QB bug and am busy building a couple of those but will be back to the disco soon.
If you have any more question don't hesitate to ask.
Mike
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10 days at tops. I have every spring, bolt, washer etc. I need right here in the shop. Lathe , mill chronograph you name it I got it. Its all about time and how much I can drop on this project. I have done several SSG already for mrod-prod-hatsan-2240 so it shouldnt be much of a problem.
10 days have come and gone no news from the hinterlands.. What's up? there are many of us waiting with eager anticipation for the news...
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In fairness to Travis, the rifle arrived at his shop Friday afternoon. I preferred the 5 days of UPS over the USPS method of turning 3 days into 3 weeks. Really happened, this year...
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In fairness to Travis, the rifle arrived at his shop Friday afternoon. I preferred the 5 days of UPS over the USPS method of turning 3 days into 3 weeks. Really happened, this year...
Not to mention it costs more USPS Priority for something of that weight.
I PM'd Travis about making them using Prod hammer optional.
Later I realized his Mrod kit doesn't include the hammer and requires you to drill out the stock piece yourself to 1/4".
I'm not entirely sure that's the plan for the Disco kit or not, but I have a couple brand new Disco hammer weights just for this purpose and offered them to Travis for development. I suspect he has some already though. Would be easier to start with the Prod weight since it's already drilled but maybe that's not an issue for him.
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His Mrod SSG actually comes with the option now of one with and without a hammer. The SSG Im trying to make is with a Prod hammer. A lot still needs to be done to them to work. First the threads had to be drilled out to 1/4" which wasn't easy as your would think even with hardened bits. And then I had to drill out the spring hole to 3/8" to accomodate a spring to fit on the bolt. Also drilled it a lot deeper than it was at least double what it was. Surprisingly this was a lot easier than the threads which doesn't make sense taking away so much more material. Next coming up a spring length and end cap to work has been a struggle with such little room to work with. I'm sure Travis will have it all taken care of but it definitely takes a lot more time than what it would on a Mrod I'm finding out.
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His Mrod SSG actually comes with the option now of one with and without a hammer. The SSG Im trying to make is with a Prod hammer. A lot still needs to be done to them to work. First the threads had to be drilled out to 1/4" which wasn't easy as your would think even with hardened bits. And then I had to drill out the spring hole to 3/8" to accomodate a spring to fit on the bolt. Also drilled it a lot deeper than it was at least double what it was. Surprisingly this was a lot easier than the threads which doesn't make sense taking away so much more material. Next coming up a spring length and end cap to work has been a struggle with such little room to work with. I'm sure Travis will have it all taken care of but it definitely takes a lot more time than what it would on a Mrod I'm finding out.
More time and more machining of that hardened weight material. That's why I've decided to to just get one from Travis and hopefully he has them made with the Prod hammer relieved for the rear breach screw like Norm was doing.
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Yep waiting with anticipation myself to see what the end result is and when it available to buy.
Mike
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hello here.. ive got my disco apart for oring service. ill try to post pics of the ssg i came up with. ill try to lay it beside a ruler. cheers
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hello here.. ive got my disco apart for oring service. ill try to post pics of the ssg i came up with. ill try to lay it beside a ruler. cheers
Lookin forward to it David... Also heard word on another airgun forum that Travis is working on the SSG now but won't be finished until after the Kentucky fun shoot. He said it was looking like it's gonna be very good.
Also the Prod hammer I'm using is one of Norms.
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Yep I'm getting close guys and I'm also using a modded prod hammer. Will finish up after the GTA but it's looking great so far.
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Yep I'm getting close guys and I'm also using a modded prod hammer. Will finish up after the GTA but it's looking great so far.
;D ;D ;D ;D ;D ;D ;D ;D ;D ;D ;D ;D ;D ;D ;D ;D ;D ;D ;D ;D
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here are pics. (http://i1190.photobucket.com/albums/z451/davidmccann1969/DSCN0231_zpsinptqryg.jpg) (http://s1190.photobucket.com/user/davidmccann1969/media/DSCN0231_zpsinptqryg.jpg.html) (http://i1190.photobucket.com/albums/z451/davidmccann1969/DSCN0223_zpsrfxucozd.jpg) (http://s1190.photobucket.com/user/davidmccann1969/media/DSCN0223_zpsrfxucozd.jpg.html) (http://i1190.photobucket.com/albums/z451/davidmccann1969/DSCN0229_zps4scztxwa.jpg) (http://s1190.photobucket.com/user/davidmccann1969/media/DSCN0229_zps4scztxwa.jpg.html)
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Yep I'm getting close guys and I'm also using a modded prod hammer. Will finish up after the GTA but it's looking great so far.
Exellent - can't wait.
Thanks Travis
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here are pics. (http://i1190.photobucket.com/albums/z451/davidmccann1969/DSCN0231_zpsinptqryg.jpg) (http://s1190.photobucket.com/user/davidmccann1969/media/DSCN0231_zpsinptqryg.jpg.html) (http://i1190.photobucket.com/albums/z451/davidmccann1969/DSCN0223_zpsrfxucozd.jpg) (http://s1190.photobucket.com/user/davidmccann1969/media/DSCN0223_zpsrfxucozd.jpg.html) (http://i1190.photobucket.com/albums/z451/davidmccann1969/DSCN0229_zps4scztxwa.jpg) (http://s1190.photobucket.com/user/davidmccann1969/media/DSCN0229_zps4scztxwa.jpg.html)
Nice work Dave.
Checking out the rest of your Photobucket pics and those stocks look handmade. If you did those yourself, I'm very impressed!
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Very nice work David and looks well thought out. one question on the SSG is the spring tension adjuster held from turning by a set screw or is it a nylock nut turned down, or is it tightened down on the bolt so it non adjustable and was played with to get the final tune and then made to that setting with everything being locked as a unit.
Mike
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Thanks David that's exactly what I wanted to know
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the nut was layed down and a tapered tip punch placed in the hole of the nut and lightly struck w/ hammer to kinda flatten the first thread a little to keep it from turning freely on the threads. just played with end cap depth / diff lengths rubber vac hose to get the gap. tighter gap seems to give more velocity, while more gap reduced velocity. thank you all for the kind words. the stocks were all done by me, with blk walnut stump and roots we dug out of the dirt, cut up, dried under the stairs for years. much time spent on those. thank you sirs.....and er um maamms. cheers ??????????
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Great job on that David, it's something to be very proud of!
It's an heirloom now.
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David
Thanks for the info and those stocks are indeed heirlooms as Tater stated. Excellent work.
Mike
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thanks guys
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Well I guess its time I posted my SSG setup and build results.....
its a basic "cartridge" type design.... there was no mods to the hammer and only changes was done to the rear cap and it was drilled and tapped to 1/2-20 so that it would completely clear the stock disco springs so that any spring changes or adjustments could be made without taking the gun apart..
the important bits... bout as simple as it gets... guiderod front and rear spring guides stop collar and preload adjustment nut... and then the rear gap set and locking nut...
(http://i148.photobucket.com/albums/s8/michael90t/Airgun/SSG/IMG_20160503_023835_zps7rmsilku.jpg)
here it is with everything installed in the gun
(http://i148.photobucket.com/albums/s8/michael90t/Airgun/SSG/IMG_20160503_024007_zpsdmvlxpa5.jpg)
uncocked
(http://i148.photobucket.com/albums/s8/michael90t/Airgun/SSG/IMG_20160503_025646_zpswcjanatf.jpg)
Cocked
(http://i148.photobucket.com/albums/s8/michael90t/Airgun/SSG/IMG_20160503_025700_zps8ygzofe5.jpg)
While its not a true "fully internal" setup there is nothing exposed to bite hands.....
and here is the shot string...
(http://i148.photobucket.com/albums/s8/michael90t/Airgun/Disco%20Double/DiscoDouble%20SSG_zpskawfyqqn.jpg)
And the Efficiency calculations
(http://i148.photobucket.com/albums/s8/michael90t/Airgun/Disco%20Double/Mikes%20SSGDD_zpsx5mppxmx.jpg)
While I feel the efficiency is extremely good it wastes a LOT of air driving a 14.3 grain pellet to 26.4 FPE... with 18.1 and the same tune it gets 31 fpe and I pick up a few shots at the end of the string for even better eff (think it was in the 1.7fpe/cuin range) but I didn't make a chart of that shot string.... or if I would detune the 18.1's to 26 fpe I would imagine I could get probably another 10-12 shots or more and easily get into the 1.8fpe/cuin efficiency ball park... but that's neither here nor there as I shoot almost exclusively 14.3 cphp because they are cheap and plentiful and the gun shoots them well......
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MichaelM
I like the design and am curious as to where the free play thumb adjuster and thumb nut are from as that looks very custom and like it was made for the gun. I already have my disco end cap drilled to the 3/8-24 that crosman use in the Prods and Mrods so going out to 1/2-20 would not be much of an issue.
Mike
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Im going to finish my buddy Marks(mobilemail) this week and would like to know what wire diameters are you having the best luck with?
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Gotta say that I am impressed with the work done here by everyone: David, Michael, Travis, and all. Good collaboration and sharing of info, along with the excellent results.
Lloyd
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Well I guess its time I posted my SSG setup and build results.....
its a basic "cartridge" type design.... there was no mods to the hammer and only changes was done to the rear cap and it was drilled and tapped to 1/2-20 so that it would completely clear the stock disco springs so that any spring changes or adjustments could be made without taking the gun apart..
the important bits... bout as simple as it gets... guiderod front and rear spring guides stop collar and preload adjustment nut... and then the rear gap set and locking nut...
(http://i148.photobucket.com/albums/s8/michael90t/Airgun/SSG/IMG_20160503_023835_zps7rmsilku.jpg)
here it is with everything installed in the gun
(http://i148.photobucket.com/albums/s8/michael90t/Airgun/SSG/IMG_20160503_024007_zpsdmvlxpa5.jpg)
uncocked
(http://i148.photobucket.com/albums/s8/michael90t/Airgun/SSG/IMG_20160503_025646_zpswcjanatf.jpg)
Cocked
(http://i148.photobucket.com/albums/s8/michael90t/Airgun/SSG/IMG_20160503_025700_zps8ygzofe5.jpg)
While its not a true "fully internal" setup there is nothing exposed to bite hands.....
and here is the shot string...
(http://i148.photobucket.com/albums/s8/michael90t/Airgun/Disco%20Double/DiscoDouble%20SSG_zpskawfyqqn.jpg)
And the Efficiency calculations
(http://i148.photobucket.com/albums/s8/michael90t/Airgun/Disco%20Double/Mikes%20SSGDD_zpsx5mppxmx.jpg)
While I feel the efficiency is extremely good it wastes a LOT of air driving a 14.3 grain pellet to 26.4 FPE... with 18.1 and the same tune it gets 31 fpe and I pick up a few shots at the end of the string for even better eff (think it was in the 1.7fpe/cuin range) but I didn't make a chart of that shot string.... or if I would detune the 18.1's to 26 fpe I would imagine I could get probably another 10-12 shots or more and easily get into the 1.8fpe/cuin efficiency ball park... but that's neither here nor there as I shoot almost exclusively 14.3 cphp because they are cheap and plentiful and the gun shoots them well......
That is an outstanding result! That's as many shots as my regulated .22 Marauder, at the same power! Is that a single or double tube disco, I can't tell from the picture.
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And the Efficiency calculations
(http://i148.photobucket.com/albums/s8/michael90t/Airgun/Disco%20Double/Mikes%20SSGDD_zpsx5mppxmx.jpg)
That is an outstanding result! That's as many shots as my regulated .22 Marauder, at the same power! Is that a single or double tube disco, I can't tell from the picture.
Looks like a Double here
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I'll jump in here, yes, Michael's gun is one of the original Disco Doubles that he won in the GTA raffle in the summer of 2012. Looks like Michael not only talks a good game, but he can back it up, too. ;)
BTW, Mark, are you the guy who won a plethora of raffle prizes at the Fun Shoot this past weekend? :o
Lloyd
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I'll jump in here, yes, Michael's gun is one of the original Disco Doubles that he won in the GTA raffle in the summer of 2012. Looks like Michael not only talks a good game, but he can back it up, too. ;)
BTW, Mark, are you the guy who won a plethora of raffle prizes at the Fun Shoot this past weekend? :o
Lloyd
Guilty as charged! In fairness, my wife won a couple of them and sent me up as her retriever! (But the rifle is MINE! ALL MINE!!!)
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I'll jump in here, yes, Michael's gun is one of the original Disco Doubles that he won in the GTA raffle in the summer of 2012. Looks like Michael not only talks a good game, but he can back it up, too. ;)
BTW, Mark, are you the guy who won a plethora of raffle prizes at the Fun Shoot this past weekend? :o
Lloyd
Guilty as charged! In fairness, my wife won a couple of them and sent me up as her retriever! (But the rifle is MINE! ALL MINE!!!)
Ha, ha. I think you and Jay were both guilty of stuffing the ballot boxes. But hey! It paid off!
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Nice. Good job sir.
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I'll jump in here, yes, Michael's gun is one of the original Disco Doubles that he won in the GTA raffle in the summer of 2012. Looks like Michael not only talks a good game, but he can back it up, too. ;)
BTW, Mark, are you the guy who won a plethora of raffle prizes at the Fun Shoot this past weekend? :o
Lloyd
Guilty as charged! In fairness, my wife won a couple of them and sent me up as her retriever! (But the rifle is MINE! ALL MINE!!!)
Ha, ha. I think you and Jay were both guilty of stuffing the ballot boxes. But hey! It paid off!
Honestly, I didn't stuff anything, I put one ticket each in several boxes. The rest is by the grace of God.
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I'll jump in here, yes, Michael's gun is one of the original Disco Doubles that he won in the GTA raffle in the summer of 2012. Looks like Michael not only talks a good game, but he can back it up, too. ;)
BTW, Mark, are you the guy who won a plethora of raffle prizes at the Fun Shoot this past weekend? :o
Lloyd
Guilty as charged! In fairness, my wife won a couple of them and sent me up as her retriever! (But the rifle is MINE! ALL MINE!!!)
Ha, ha. I think you and Jay were both guilty of stuffing the ballot boxes. But hey! It paid off!
Honestly, I didn't stuff anything, I put one ticket each in several boxes. The rest is by the grace of God.
It appears you were in his favor last weekend then .
Mike
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That was my conclusion too!
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MichaelM
I like the design and am curious as to where the free play thumb adjuster and thumb nut are from as that looks very custom and like it was made for the gun. I already have my disco end cap drilled to the 3/8-24 that crosman use in the Prods and Mrods so going out to 1/2-20 would not be much of an issue.
Mike
It is indeed custom... machined it from delrin
Im going to finish my buddy Marks(mobilemail) this week and would like to know what wire diameters are you having the best luck with?
I BELIEVE its a .039 12 coil spring.... almost positive its the same spring that Rstern used to recommend for 2200 psi fills..... The valve is a cool custom setup that would be more at home in a bigbore setup then in the .22 lol it flows so well as a matter of fact that I have to use a tiny .120 transfer port to get such a nice shot string as anything bigger would make it WAY to peaky on the curve
And yes it IS a disco double! IMHO its the best thing that can be done to a disco....
thanks for the kind words everyone... I know there is a lot more efficiency to be found with heavier pellets and could reach outstanding numbers if I wasn't such a cheap *** and would shoot 18.1's lol but what can I say... 6 bucks or so for a tin of cphp's and all i ever really shoot is 20 yards in the back yard and they work just fine :)
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MichaelM
I like the design and am curious as to where the free play thumb adjuster and thumb nut are from as that looks very custom and like it was made for the gun. I already have my disco end cap drilled to the 3/8-24 that crosman use in the Prods and Mrods so going out to 1/2-20 would not be much of an issue.
Mike
It is indeed custom... machined it from delrin
Im going to finish my buddy Marks(mobilemail) this week and would like to know what wire diameters are you having the best luck with?
I BELIEVE its a .039 12 coil spring.... almost positive its the same spring that Rstern used to recommend for 2200 psi fills..... The valve is a cool custom setup that would be more at home in a bigbore setup then in the .22 lol it flows so well as a matter of fact that I have to use a tiny .120 transfer port to get such a nice shot string as anything bigger would make it WAY to peaky on the curve
And yes it IS a disco double! IMHO its the best thing that can be done to a disco....
thanks for the kind words everyone... I know there is a lot more efficiency to be found with heavier pellets and could reach outstanding numbers if I wasn't such a cheap *** and would shoot 18.1's lol but what can I say... 6 bucks or so for a tin of cphp's and all i ever really shoot is 20 yards in the back yard and they work just fine :)
All I can say is it looks like steel and I like the fact that it delrin even better since it less weight and much easier to machine and knurl as well. very nice indeed.
mike
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All I can say is it looks like steel and I like the fact that it delrin even better since it less weight and much easier to machine and knurl as well. very nice indeed.
mike
Believe it or not I find delrin to be a pain in the butt to knurl nicely!!! While it machines so nice it even makes a hack like myself look like he knows what he is doing around a lathe... to get nice deep knurls its a pain and seems to take 4 times the pressure one would think to get it to take.... me thinks I need to make/buy a scissor type knurling holder instead of my straight push type.. but then again I like the spiral look of using a single wheel sometimes too....
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All I can say is it looks like steel and I like the fact that it delrin even better since it less weight and much easier to machine and knurl as well. very nice indeed.
mike
Believe it or not I find delrin to be a pain in the butt to knurl nicely!!! While it machines so nice it even makes a hack like myself look like he knows what he is doing around a lathe... to get nice deep knurls its a pain and seems to take 4 times the pressure one would think to get it to take.... me thinks I need to make/buy a scissor type knurling holder instead of my straight push type.. but then again I like the spiral look of using a single wheel sometimes too....
I can see where delrin would take more pressure to knurl since its more resilient in retaining its shape but you seem to have the process under control quite well IMO.
Mike
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Travis, Any info on the WAR SSG
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I talked to Travis today about it. (Not to speak on his behalf. ;) )
He's been pretty buried keeping up with the FLEX orders, so he's had to take care of those customers before he wraps up this project. It sounds like it's all done but just final testing. And honestly, if I were one of the guys waiting for a FLEX, that's exactly what I would want him to be doing. (In fact, I hope to be one of those guys one day.)
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I talked to Travis today about it. (Not to speak on his behalf. ;) )
He's been pretty buried keeping up with the FLEX orders, so he's had to take care of those customers before he wraps up this project. It sounds like it's all done but just final testing. And honestly, if I were one of the guys waiting for a FLEX, that's exactly what I would want him to be doing. (In fact, I hope to be one of those guys one day.)
Sorry guys - Travis is getting my Flex .25 shipped out today ;D
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You don't look very sorry!! ::)
I'm still figuring out how to slip the cost past the wife detector... :-\
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I'm still figuring out how to slip the cost past the wife detector... :-\
I bought mine 1 gun at a time. Over the past 2 years I picked up a bunch of different lower cost gun, tuned them, shot them and then over the past 2 weeks I sold a bunch of them. Basically a "savings plan" for the Flex. And now a bunch of different guys have some nice guns.
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I have news! Travis called and sent me the shot string with the prototype SSG. It was like talking to a kid, he was pretty excited. The rifle I sent him had a homemade power adjuster in it that had the rifle set to shoot about 20 shots at ~800fps, the SSG added another 50% to that. My wife's bone stock disco only gets about a dozen shots per fill right now, so I can't wait to put one in her gun.
Travis also said it made the Disco quiet enough that you could possibly shoot it without an LDC. I would take that with a grain of salt with anyone else, but Travis really hates noisy rifles (there is a thread about that somewhere), so I believe it.
Price point is going to be $49.95 (I think he said that's the shipped price, but double check with Travis@ www.wickedairrifles.com (http://www.wickedairrifles.com)) If you're like me and you don't have the time, tools or talent to make your own, the gained efficiency (saved pump strokes or trips to the dive shop) makes it a no-brainer.
Here is the hard data:
The "before" shot string, as sent to Travis
785 815 798
792 814 789
802 814 780
795 815 771
804 815 755
806 815
811 811
804 806
814 805
812 795
With Crosman 14.3gr pellet, 2000-1200psi I made this shot string myself before I sent off the rifle
SSG shot string at same power (Travis provided this and the next one)
Created: 06/08/16 03:42 PM
Description: SSG disco
Notes 1: 2k to 1.2k
Notes 2: Distance to Chrono(FT): 1.00
Ballistic Coefficient: 1.000 Bullet Weight(gr): 14.30
Temp: N/A °F BP: N/A inHg Altitude: 0.00
# FPS FT-LBS PF
33 782 19.42 11.18
32 786 19.62 11.24
31 801 20.38 11.45
30 796 20.12 11.38
29 788 19.72 11.27
28 794 20.02 11.35
27 804 20.53 11.50
26 812 20.94 11.61
25 808 20.73 11.55
24 806 20.63 11.53
23 809 20.78 11.57
22 816 21.15 11.67
21 802 20.43 11.47
20 808 20.73 11.55
19 800 20.33 11.44
18 813 20.99 11.63
17 813 20.99 11.63
16 806 20.63 11.53
15 806 20.63 11.53
14 798 20.22 11.41
13 798 20.22 11.41
12 801 20.38 11.45
11 814 21.04 11.64
10 812 20.94 11.61
9 802 20.43 11.47
8 795 20.07 11.37
7 792 19.92 11.33
6 806 20.63 11.53
5 792 19.92 11.33
4 791 19.87 11.31
3 797 20.17 11.40
2 789 19.77 11.28
1 780 19.32 11.15
Average: 800.5 FPS SD: 9.6 FPS
Min: 780 FPS Max: 816 FPS
Spread: 36 FPS Shot/sec: 0.1 True
MV: 801 FPS Group Size (in): 0.00
SSG Shot string with a little more power
Created: 06/08/16 11:12 AM
Description: SSG disco
Notes 1: 14.3 Cp
Notes 2: Distance to Chrono(FT): 1.00
Ballistic Coefficient: 1.000
Bullet Weight(gr): 14.30
Temp: N/A °F BP: N/A inHg
Altitude: 0.00
# FPS FT-LBS PF
20 820 21.35 11.73
19 819 21.30 11.71
18 822 21.46 11.75
17 825 21.62 11.80
16 823 21.51 11.77
15 828 21.77 11.84
14 834 22.09 11.93
13 834 22.09 11.93
12 839 22.36 12.00
11 836 22.20 11.95
10 832 21.98 11.90
9 836 22.20 11.95
8 833 22.04 11.91
7 831 21.93 11.88
6 831 21.93 11.88
5 833 22.04 11.91
4 831 21.93 11.88
3 827 21.72 11.83
2 826 21.67 11.81
1 ERROR 10
Average: 829.5 FPS SD: 5.7 FPS
Min: 819 FPS Max: 839 FPS
Spread: 20 FPS Shot/sec: 0.1
True MV: 830 FPS Group Size (in): 0.00
Since my wife mostly shoots in the basement or back yard with me, I think I wll see if hers will tune down to 550-600fps. If it does I'll share my results with the install and adjustment.
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Here are some pics Travis sent me of the SSG parts. He's going to add a plastic cap to the final product just to make it look nice and avoid any possibility of gotchas. (I don't think it reaches out far enough for a gotcha, but it will look cooler.)
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I know it took forever but Im really cramped for time these days. These two tunes were done ONLY by adjusting gap adjuster in or out no spring changes or adjustments. I found a balance point that will allow me to ship the Disco SSG nearly tuned and you will only need to fill to your middle fill pressure set your max speed you want and adjust your gap and DONE! Only bad thing is I couldnt keep it all internall with out a serious price increase so 1/4 inch of rod will protrude but I will supply a black rubber cap to cover it though it is no where near your hand(safety first). $49.95 shipped and of course like all my products free advice via phone.
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Travis
Are they listed for sale on your website yet
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Travis
Are they listed for sale on your website yet
I did a search for "SSG" on Wicked Air Rifles and nothing came up.
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Not yet listed I had to order parts from crosman and that will take about a week BUT just email me and I will put you on the list when I run the first batch.
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Travis
Are they listed for sale on your website yet
I did a search for "SSG" on Wicked Air Rifles and nothing came up.
The Mrod gen 1 and 2 SSGs are on his site but not the disco one yet.
Travis
Sounds good on the email to be on the list.
Thanks Mike
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Hey Travis, remember that 10 minutes you got to sit down? Break's over! :D :D
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I should be posting pics later tonight or tommorrow of a new fully internal SSG setup for the disco
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As promised!! fully internal SSG for the disco.... I used a prod hammer for the prototype but if I was to make these I would make the hammer myself because almost 20 bucks a pop the prod/challenger hammer is pricey not to mention the way hardened hammer plays *(&^ on drill bits trying to drill the threads out, The Mrod hammers are not hardened nearly as much as these are... ate one bit completely attempting it lol..... Also could make a lightweight hammer too but to be honest the disco hammer isn't that massive... anyways on to the pics!
Hammer guide rod and nylock nut for preload adjustment... and the rear plug and aluminum machined gap adjustment, could also make from delrin if a black gap adjust was wanted... but machined this one from aluminum just because it looks good with my polished rear plug ..
(http://i148.photobucket.com/albums/s8/michael90t/Airgun/SSG/IMG_20160612_230151_zpsydpfyxi0.jpg)
this is what it looks like installed.... the setscrew is what locks the gap adjustment after its been set.... also its long so that when you adjust the preload it also works as a stop for the nylock nut so you just need to use a flathead to adjust the preload....
(http://i148.photobucket.com/albums/s8/michael90t/Airgun/SSG/IMG_20160612_225649_zpsq7kgpkta.jpg)
(http://i148.photobucket.com/albums/s8/michael90t/Airgun/SSG/IMG_20160612_225639_zpsclt6zode.jpg)
thats it pretty simple... uses stock disco size springs so you can put whatever spring you want in there for the tune your trying to get.... other then that it works like every other SSG... set your preload for your powerlevels/tune, set your gap, shoot........
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They look great!
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As promised!! fully internal SSG for the disco.... I used a prod hammer for the prototype but if I was to make these I would make the hammer myself because almost 20 bucks a pop the prod/challenger hammer is pricey not to mention the way hardened hammer plays *(&^ on drill bits trying to drill the threads out, The Mrod hammers are not hardened nearly as much as these are... ate one bit completely attempting it lol..... Also could make a lightweight hammer too but to be honest the disco hammer isn't that massive... anyways on to the pics!
Hammer guide rod and nylock nut for preload adjustment... and the rear plug and aluminum machined gap adjustment, could also make from delrin if a black gap adjust was wanted... but machined this one from aluminum just because it looks good with my polished rear plug ..
(http://i148.photobucket.com/albums/s8/michael90t/Airgun/SSG/IMG_20160612_230151_zpsydpfyxi0.jpg)
this is what it looks like installed.... the setscrew is what locks the gap adjustment after its been set.... also its long so that when you adjust the preload it also works as a stop for the nylock nut so you just need to use a flathead to adjust the preload....
(http://i148.photobucket.com/albums/s8/michael90t/Airgun/SSG/IMG_20160612_225649_zpsq7kgpkta.jpg)
(http://i148.photobucket.com/albums/s8/michael90t/Airgun/SSG/IMG_20160612_225639_zpsclt6zode.jpg)
thats it pretty simple... uses stock disco size springs so you can put whatever spring you want in there for the tune your trying to get.... other then that it works like every other SSG... set your preload for your powerlevels/tune, set your gap, shoot........
So, are you going to sell these? The project came out beautifully, but I would not be able to re-create it... my machining kung fu is very very weak....like...doesn't exist.
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Travis
Are they listed for sale on your website yet
I did a search for "SSG" on Wicked Air Rifles and nothing came up.
The Mrod gen 1 and 2 SSGs are on his site but not the disco one yet.
Travis
Sounds good on the email to be on the list.
Thanks Mike
I can't find them for the Mrods either ???
Ed
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As promised!! fully internal SSG for the disco.... I used a prod hammer for the prototype but if I was to make these I would make the hammer myself because almost 20 bucks a pop the prod/challenger hammer is pricey not to mention the way hardened hammer plays *(&^ on drill bits trying to drill the threads out, The Mrod hammers are not hardened nearly as much as these are... ate one bit completely attempting it lol..... Also could make a lightweight hammer too but to be honest the disco hammer isn't that massive... anyways on to the pics!
Hammer guide rod and nylock nut for preload adjustment... and the rear plug and aluminum machined gap adjustment, could also make from delrin if a black gap adjust was wanted... but machined this one from aluminum just because it looks good with my polished rear plug ..
(http://i148.photobucket.com/albums/s8/michael90t/Airgun/SSG/IMG_20160612_230151_zpsydpfyxi0.jpg)
this is what it looks like installed.... the setscrew is what locks the gap adjustment after its been set.... also its long so that when you adjust the preload it also works as a stop for the nylock nut so you just need to use a flathead to adjust the preload....
(http://i148.photobucket.com/albums/s8/michael90t/Airgun/SSG/IMG_20160612_225649_zpsq7kgpkta.jpg)
(http://i148.photobucket.com/albums/s8/michael90t/Airgun/SSG/IMG_20160612_225639_zpsclt6zode.jpg)
thats it pretty simple... uses stock disco size springs so you can put whatever spring you want in there for the tune your trying to get.... other then that it works like every other SSG... set your preload for your powerlevels/tune, set your gap, shoot........
So, are you going to sell these? The project came out beautifully, but I would not be able to re-create it... my machining kung fu is very very weak....like...doesn't exist.
+1 same question. I have to stay fully internal design and stock size cap due to my Boyds stock. I don't want to go grinding on it to clearance it.
Very nice looking work BTW. If you decide to make them for sale, please let us know. Paypal ready.
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Mike-I'd be a buyer as well should you decide to sell them. Very nice clean design!
Ed
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Looks real good Michael, nice work.
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I would be more then happy to make these and sell them to you guys.... this gun will be shooting in a field target even this coming weekend and I may have a few tweaks to the overall design... already have a few minor things I want to change and a picture in my head of the hammer design i will make...
If I make these the hammer will most likely not be a prod/challenger hammer... they are about 18 bucks a pop and would drive the costs up... because of the price per unit and the amount of machining that needs to be done anyways I am thinking it would be cheaper/more economical to make the entire hammer in house... I already have some ideas of a nice steel/delrin hybrid that would be easy to make and probably be better overall.....
I think if I make the whole thing in house I could get them to you guys in the $60 dollar price range maybe a touch more but it should be in that ball park....
if you guys are serious I can look at the rules in the hobbyist classified gate and maybe do a group buy... take the first 5 guys to get some units in your hands then you all can beat on them and find any weak spots ( lol those never show up until different people beat on things...)
send me a PM so I can keep track if you guys are interested and I will get things rolling!!
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Looks great and glad you were able to keep everything internal...look forward to some results!
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I got the go ahead for a group buy thread...
can be found here
http://www.gatewaytoairguns.org/GTA/index.php?topic=110525.0 (http://www.gatewaytoairguns.org/GTA/index.php?topic=110525.0)
only 5 slots for the first run!!
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I got the go ahead for a group buy thread...
can be found here
http://www.gatewaytoairguns.org/GTA/index.php?topic=110525.0 (http://www.gatewaytoairguns.org/GTA/index.php?topic=110525.0)
only 5 slots for the first run!!
PM sent as i want to included in the group buy. I just had a question first.
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Adding Edit: Walmart Crosman Premier HP 14.30
Stock Discovery
FPS PSI Percentage
782.6 1700 Start 4 %
780.7
779.1
774.9
781.9 1600/1650 Start 3.5%
791.3 Start 3%
794.6
789.2
792.3
792.8
791.8
793.8
794.8
797
796
791
803.9 1350
801.5
793.1
802.7
801.7
803.4
807.2
811.3 1100
803
803.7
805.3
790.5
792.1
792.6
793.1
786 1025
788.7
786 End 3%
785.1 1000 End 3.5%
778.4 End 4%
769.8 950
Spring Preload 1.26"
Gap 0.025"
Average FPS % Shots FPE
793.1 4 35 20
795.4 3.5 31 20.1
796.2 3 28 20.1
Thoughts so far.
It takes a bit to get it dialed in and I had trouble with the concept at first. Adjusting the gap was hard because I was hitting the rear of the hammer sooner than I thought. I then switched measuring from the back of the gap adjuster (end of guide bolt to back of guide adjuster) using dial calipers with guide at rest to determine length. I then screwed in the gap adjuster and measured until I could see a change as I hit the rear of the hammer. Once I had that down, it was much easier to start dialing it in.
The only thing I don't like is the amount of force required to pull the bolt back, it is not terrible, however there is a marked difference and makes me wonder about wear and tear on the bolt/handle. After shooting 80 pellets I was feeling it.
This is only preliminary and I have more to do. I want to see if I can reduce the cocking force and once that is done I will drill my gap adjuster deeper so the guide will be mostly recessed to reduce any pinching possibilities. I'm using a RVA as the SSG, which is probably why I was having conceptual issues.
Before this, using just the RVA and preloading the spring and starting at 1800 PSI shooting down to 1050 PSI was averaging 801 FPS (at 3.5%) getting around 21 shots.
I will post again with pictures once I’m done, it will be fairly similar to what you have already seen as I’m just copying. I hope my format makes sense.
Dave
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Stock Discovery
FPS PSI Percentage
782.6 1700 Start 4 %
780.7
779.1
774.9
781.9 1600/1650 Start 3.5%
791.3 Start 3%
794.6
789.2
792.3
792.8
791.8
793.8
794.8
797
796
791
803.9 1350
801.5
793.1
802.7
801.7
803.4
807.2
811.3 1100
803
803.7
805.3
790.5
792.1
792.6
793.1
786 1025
788.7
786 End 3%
785.1 1000 End 3.5%
778.4 End 4%
769.8 950
Spring Preload 1.26"
Gap 0.025"
Average FPS % Shots FPE
793.1 4 35 20
795.4 3.5 31 20.1
796.2 3 28 20.1
Thoughts so far.
It takes a bit to get it dialed in and I had trouble with the concept at first. Adjusting the gap was hard because I was hitting the rear of the hammer sooner than I thought. I then switched measuring from the back of the gap adjuster (end of guide bolt to back of guide adjuster) using dial calipers with guide at rest to determine length. I then screwed in the gap adjuster and measured until I could see a change as I hit the rear of the hammer. Once I had that down, it was much easier to start dialing it in.
The only thing I don't like is the amount of force required to pull the bolt back, it is not terrible, however there is a marked difference and makes me wonder about wear and tear on the bolt/handle. After shooting 80 pellets I was feeling it.
This is only preliminary and I have more to do. I want to see if I can reduce the cocking force and once that is done I will drill my gap adjuster deeper so the guide will be mostly recessed to reduce any pinching possibilities. I'm using the my RVA as the SSG, which is probably why I was having conceptual issues.
Before this, using just the RVA and preloading the spring and starting at 1800 PSI shooting down to 1050 PSI was averaging 801 FPS (at 3.5%) getting around 21 shots.
I will post again with pictures once I’m done, it will be fairly similar to what you have already seen as I’m just copying. I hope my format makes sense.
Dave
Thank you for the info.
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I would like to have one if it is all internal, I have a thumb hole stock and no way will it work without cuttting on stock if its not all internal, and I won't cut on stock. Cant wait!!!!!!! Gaylon
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I would like to have one if it is all internal, I have a thumb hole stock and no way will it work without cuttting on stock if its not all internal, and I won't cut on stock. Cant wait!!!!!!! Gaylon
well... you're in luck :) after the first 5 orders from the group buy are filled I will be offering more... it will be a few weeks but will give everyone a heads up !! They may go up in price a bit but will still be in the $60 ballpark.....
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I would like to have one if it is all internal, I have a thumb hole stock and no way will it work without cuttting on stock if its not all internal, and I won't cut on stock. Cant wait!!!!!!! Gaylon
well... you're in luck :) after the first 5 orders from the group buy are filled I will be offering more... it will be a few weeks but will give everyone a heads up !! They may go up in price a bit but will still be in the $60 ballpark.....
Glad to hear that. By then I'll be ready to order one. ;) My rifle hasn't even shipped yet, Crosman's a slow shipper............
Ed
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Anything new on this thread?
Travis, are you shipping your version yet?
Michael, same question.
Maybe photos of the final versions.
Waiting patiently with worms on tongue (with baited breath) LOL
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After going through the proto work, I've never seen Travis post the product on his website. Honestly I think he's up to his armpits in alligators between filling the flex orders, selling the marauder ssg, and any tuning work he has going on. I think he gave up sleep for 2016. :-)
I look forward to the one Michael's working on, it will go in my wife's rifle. Won't she love me???
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After going through the proto work, I've never seen Travis post the product on his website. Honestly I think he's up to his armpits in alligators between filling the flex orders, selling the marauder ssg, and any tuning work he has going on. I think he gave up sleep for 2016. :-)
I look forward to the one Michael's working on, it will go in my wife's rifle. Won't she love me???
Don't forget about the WARPs ;) I might be getting one of Michaels once i see how they do.
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Don't forget about the WARPs ;) I might be getting one of Michaels once i see how they do.
Who could forget about the WARPS, there's too much bragging going on! ;D ;D ;D (Which is exactly what I would be doing if I had one! ::) )
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Don't forget about the WARPs ;) I might be getting one of Michaels once i see how they do.
Who could forget about the WARPS, there's too much bragging going on! ;D ;D ;D (Which is exactly what I would be doing if I had one! ::) )
Ahh...IDK...shoot it? ;)
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Hey Michael...did you ever get the internal disco SSG run done? I hav n't looked at this thread in a while and wondered what the latest was. My original external SSG still works great but might be up for a project this winter when it gets cold and snowy up here.
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Put me down for one in the second run.
Mike
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Put me down for one in the second run.
Mike
Hey Michael...did you ever get the internal disco SSG run done? I hav n't looked at this thread in a while and wondered what the latest was. My original external SSG still works great but might be up for a project this winter when it gets cold and snowy up here.
here is the thread for the ones I am building... read through it lol it has all the information listed.... the first batch will be done in days then I will start making them and putting them up as they are finished.....
http://www.gatewaytoairguns.org/GTA/index.php?topic=110547.0 (http://www.gatewaytoairguns.org/GTA/index.php?topic=110547.0)
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So who all has a Disco SSG that they are selling? I'm happy with my mine for now but would love to see the internal latest and greatest. Winter coming here in Canada and will need a project for those snowy days lol
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MichaelM's device is the only disco SSG that I have heard of that's fully internal. My Disco has a WAR-installed SSG that comes close, with just a short stub out the back.
There may be other fully internal ones out there, but I'll bet MichaeilM will testify to the gratuitous engineering they had to do to make it work!
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Thanks...Mine sticks out the back but I have a nylon nut on the back that is rounded and I have cut it as short as possible. I still might make a shroud over it for safety, although I have never had a problem.