Gen II Internal DIY SSG Mod Detailed Build and Instructions

[triggertreat]

Thanks for the update Tony!!  Great info for those on the fence.

One thing I did to smooth out the edges of the 1/4" hammer hole was to follow up with a 1/2" bit just to knock the sharp edges off.  That made the bolt slide across the edges smoother.  For the interior edge, you might drop down to the next size bit for easier entry.  I did use a 1/2" bit on both sides, but had to power through the interior side and it was not easy to do.

Glad to hear the instructions are sufficient to accomplish the build and tuning.  I was hopeful that they were and tried to keep them as concise as possible.

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I actually used a dremel polishing stone and it beveled both the interior and exterior of the 1/4 hammer hole. I wish I had a 1/4 inch stone to slide in the whole itself though. I used my worksharp belt sander to make the bolt look like a mirror.

Great tip Tony.  I think you'll agree with my experiences that the hammer sleeve's close tolerance to the bolt takes care of the rough hammer hole edges for the most part.  This is because the sleeve removes the hammer tilt that causes the problem with the rough edges.  If you go without the hammer sleeve, the smoothness of the hole's edges is very important to get the best results.  Having the interior of the hole really smooth is very important.  I've used a steel dowel wrapped with sandpaper to smooth out my hammer's hole.  Drilling out the threads carefully to begin with is important, but it still needs smoothing out more too.

[triggertreat]

Reporting back with my findings on the 2" 11# spring, on the .25 cal I could only get 780ish fps max, so I swapped back to the 16# spring which I don't mind at all and am getting my desired 800-820 fps tune, a 845-865fps, and a 895-925 tune if I so desire.

I suppose the 11# spring would work for .177 or .22 cal. The 16# spring is going to be what I settle with for the time being. I may give the 11# spring another go some time who knows.

Also I am not using the F.A.M.E. mod in some of my recent tests as I have noticed its not necessary with the 1/2" spacer in the hammer. I do however still use a 1/4" water line tube on the cocking lug to keep the hammer from wiggling so much.

I was thinking that would be your findings with the 11lb.  The 2.5" 12.5lb uncut gets the velocity up better for a good ES on a medium to medium high velocity tune on the .22 cal.  Thanks for posting your findings.

The 1/2" hammer sleeve does sound good and you know I have them in my possession.  What kind of ES numbers are you getting?  Sure would like to see a full string.  It would be great to eliminate the F.A.M.E. mod, but the hammer would have to glide really, really smooth with the heavier springs for me to do so.  I have recently received and am now testing the new F.I.F.H (F.A.M.E. Inspired Floating Hammer).  It's going to be awhile before I can test them.  The F.I.F.H is looking pretty good so far, but is not a DIY mod like the F.A.M.E. is

[ackuric]

I keep my Extreme spread under 2.5% personally and my lowest SD on a 16 shot mid-range power tune was 2.0...basically that of a regulated gun's sd, most times my SD ends up around 4-6 though.

I can say this, I achieve repeat numbers (back to back) quite often, and on one of my latest strings saw repeat numbers 3x in a row...granted the decimal changed on one of them, still quite a feat (or luck of the draw with pellet weight), and my Climb into my curve is generally a 1-3 SD until it peaks, with slight bounce back and forth between peak and mid curve until it curves back down more sharply with a 4-6 SD.

My efficiency is currently 1.91 FPE / cu in @ 810 fps avg, using 22 psi per shot for 40 shots. What kind of efficiency are you getting?

Can't wait to hear your findings on the F.I.F.H mod, although I doubt this is a route I'd ever go due to it not being D.I.Y...nor do I see it providing any extra benefit to my current configuration. What I personally need is a regulator and a modified valve to give me the same shot count as my current tune with a few more fps and a half the ES. The only way anyone's achieving a 1-1.5% ES over a really high shot count is regulated. For now..I'm happy with my 2.5% high shot count.

[triggertreat]

I've only had time to do one quick tune with the F.I.F.H so far, but here are the results:



I just threw it in after a quick adjustment of the set screws to match my air tube.  I set the peak FPS at 2550 psi then filled and ran the string.  I will spend more time adjusting the hammer's set screws along with adjusting the tune more and will see how far I can go with it.  The cocking is just as smooth as the F.A.M.E. mod.  You can see the air used per shot.  30 shots averaging 22 psi per shot is not bad for a 31 FPE average on a .22 cal.  1.36% ES is the lowest I've ever gotten with that much power too.

[ackuric]

Running your numbers brings me to 1.6 fpe/cu in and 22 psi used per shot for 31 fpe, not bad at all...but I am using the same amount of air to toss a much heavier pellet (25.4gr) at 37 fpe / 810 fps, and on a 30 shot tune I see a %1.5< ES. Guess us .25 cal's are more efficient than .22's.

[triggertreat]

That's fine by me.  I don't care anything about being the best or having the best.  I'd rather that title go to someone else.  I'm just posting my mods and the results I get for anyone interested.  I've never been much interested in a .25 cal because of the low shot count and being a hand pumper.  Also, they are overkill for my backyard needs and louder than my .22 cal from what I've read.  For what it's worth, I have two large DIY vinyl tubes in my air tube to reduce/eliminate the ping.  These take up some air space as well.

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[ackuric]

.25 cal does not have low shot count (40-50 shot tunes easily possible), as well as its very backyard friendly, just as much as a .22...the only noise increase is really the 7-10fpe noticed down range, which if I want to shoot in my backyard at < 25 yards, I detune to my .25 cal to a 12 FPE gun which is uber quiet...provides tons of shots and is within a dime all day.

I also have an aftermarket Depinger in my .25 cal which reduces my air capacity as well.

I'm not trying to say which is better, .22 or .25 thats not what this thread is about, its about the DIY SSG and I simply state my observations and notes. The main reason I went with a .25 cal over a .22 is because it does not require an aftermarket barrel to perform, and also has more usability imo, since I can tune from 9 FPE to 59 FPE if I so please. Having a 50 FPE cushion to tune with allows me a lot of different options.

[triggertreat]

That's great but is getting off topic with this thread.  I created this thread for the Gen II DIY SSG mod.  I would like to stay focused on that mod here.  There are plenty of other threads focused more on the benefits of a .25 cal verses a .22 cal.  Thanks!

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DIY F.A.M.E. Mod Build

[triggertreat]

Wrapping up the year and looking back on my accomplishments this year with designing and building the DIY SSG and F.A.M.E. mods for the Marauders, I decided to compile and post some of the strings I was able to get with these mods.  I will say that most of the strings were with the F.I.F.H. hammer designed by SynRodSteve that was inspired by the F.A.M.E. mod, hence the name Fame Inspired Floating Hammer.  The string results are the same whether I used the F.A.M.E. mod or the F.I.F.H. hammer from Steve. My current DIY SSG setup is with the F.I.F.H. hammer and has been for many months.  You can PM SynRodSteve if interested in your own F.I.F.H. hammer.

Here is what my current DIY SSG with the F.I.F.H. hammer looks like:  http://www.gatewaytoairguns.org/GTA/index.php?topic=113888.msg1121394#msg1121394

All of the strings are with my non-regulated Synrod that has a stock valve and port sizing.  The fills were from 2950-3000psi shot down to 2200-2000psi.   many of the shots in each string are within 2% ES. 
 


I have detailed build instruction links in my previous post if interested.  Happy New Year to All

[aceflier]

Hello Trig I tried this tonight but with the parts listed I was not able to get the gap adjusted to the poppet pin. It ends up running out of threads. I'm using a .25cal if that matters at all. Maybe need a 3/4" length gap adjuster? I'll attempt a string tomorrow. IDon't think I have a strong enough spring either. I cut down a 10lb spring and stretched it a bit. Thanks for sharing your SSG.

[triggertreat]

How long is your bolts total length?  Do you have a Gen 2?  You need to start at least with a 12.lb spring then go up from there if needed based on desired velocity.

[aceflier]

Yes gen 2. The SS bolt is 2.63" according to my calipers. I'll look into a larger spring I have to recut the spring adjuster slot anyways I made it to wide and it wont turn so have to take apart to adjust lol. First try bugs I guess. I'm going to order a new hammer from crossman since I drilled this one out to toy around. I dont know what kind of spring it would take to get me up to 80fpe but even this 10lb is about as hard to cock as shorty SSS.

[triggertreat]

Something is a miss. Maybe you shaved the bolt head down?  First time I have heard of this issue and many have built it.  You could always go with the next length gap adjuster to solve.


80 FPE,  I assume you are opening up the ports.  If not, get ready for some hard cocking cause you're gonna need a big spring.

[aceflier]

I can get 80fpe with short's SSS down to 40fpe. Just looking into other ways to get there. I'm planning on around 45fpe for the 25gr and 60fpe for the 34gr JSB's. Since I have the Texan I really dont need more than that out of the mrod. I have not filed anything on the bolt. Yes I have .187 ports throughout and hogged valve.  I'll report back tomorrow with a short baseline 2400psi start point.

[triggertreat]

With the SSG you are fighting the additional bolt mass and gap with the spring. I am not sure of the spring needed with your setup.

[aceflier]

I shot 3 quick shots before work with the 10lb spring and 2300psi and was at 865fps. Will keep at it and use this spring and setup for low power tuning. I'll order a 16lb for higher power. I'll report back with a lower power tune today.

[ackuric]

I use 2" springs that are SO SO SO much easier to cock than 2.5" springs of the same rating

2.5" spring @ 10lb = 1 lb for every .25 of spring...

2" spring @ 10 lbs = 1 lb for every .2 of spring....

So if you, in an mrod, are cocking .7 inches (with a .05 gap) then that means...

On the 2.5" spring with 0 pre-load you get 2.5 lbs of spring force from cocking this distance
On the 2" spring with 0 pre-load you get 3.5 lbs of spring force cocking from this distance

It's easier to cock LESS distance for MORE rating as distance is a huge factor as well as spring stability which longer springs DON'T have, they fatigue really quick, they feel softer and more wobbly.../end rant

[aceflier]

Well, figured out why I can't get 0 gap. I picked up the wrong length! I got 3/8" lol. Back to the drill press on lunch break to drill that agonizing 1/8" hole in the gap adjuster.

[ackuric]

Well, figured out why I can't get 0 gap. I picked up the wrong length! I got 3/8" lol. Back to the drill press on lunch break to drill that agonizing 1/8" hole in the gap adjuster.

Oh man, I feel your pain! I just drilled a new gap adjuster for myself and my custom SSG last night, it's 1/4" instead of the 1/2" Keith uses in his, although it was easier, I do them by hand so it took me around an hour! Now I have to drill a 1/4"+ pocket around half way through this 1/4" one...UGH!

[triggertreat]

Well, figured out why I can't get 0 gap. I picked up the wrong length! I got 3/8" lol. Back to the drill press on lunch break to drill that agonizing 1/8" hole in the gap adjuster.

Lol I knew it was something.  I did drill out the end cap to allow for the most spring space and also to keep the spring adjuster from catching on anything for the best ES.  The longer spring space allows for the most spring length and easiest cocking.  You can even get a 3" spring and cut it off for what you need to fit in there.  I have cut a spring longer than the bolt and compressed it down before installing the spring adjuster which gave me a head start on spring preload for more power.