GTA
All Springer/NP/PCP Air Gun Discussion General => PCP/CO2/HPA Air Gun Gates "The Darkside" => Topic started by: Baco on January 21, 2023, 01:10:26 PM
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first time I'm doing this, thought it was simpler 😒
the hole on the second pic is the same 3.5mm as the tp and barrel, the internal hole where the poppet seats is concave and ends at 4.5mm, valve stem is 3mm so around 3.5mm equivalent on that passage discounting valve stem area
my question is would you open that hole where the poppet seats and can it be done with a hand drill without compromising the seal?
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A common rule of thumb for porting a regulated airgun is to go for the equivalent of about 75% of the bore diameter. For pellets, that is. For slugs, something closer to 100% of the caliber is advisable. I'll proceed with the assumption you will be shooting pellets for the most part.
If this is a .177 caliber gun, plugging your numbers into my little spreadsheet shows the valve throat minus the stem produce a value that precisely matches the 75% guidance (referring to the red highlighted cell...but that says 56% though, right? Yes, the 56% calculation of area is equivalent to 75% of the bore diameter because 0.75*0.75 = 0.56).
(https://i.imgur.com/h4G1L1Z.gif)
Going a little larger would be helpful if you are looking to maximize power but if you are unsure, try it like it is to see what it will do.
Of course if this is a .22 cal, you will almost certainly want to increase the porting. To know if that is in the cards, we will need to know the poppet diameter (__mm) and hopefully also what it is made of. A closeup picture may help with the latter.
Meanwhile here's a copy of the spreadsheet if you want to tinker with the numbers.
https://www.dropbox.com/scl/fi/t2mg6jphsrk4v4z3yaob2/porting-worksheet-Baco.xls?dl=0&rlkey=j4m7mqw6vl8bfcveaa6obxqcc (https://www.dropbox.com/scl/fi/t2mg6jphsrk4v4z3yaob2/porting-worksheet-Baco.xls?dl=0&rlkey=j4m7mqw6vl8bfcveaa6obxqcc)
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Thanks nervoustrigger
i was nervous and before seeing your reply i went and drilled everything "throat", exhaust, tp and receiver
it's a .25 so plugging your numbers we went from 56% to 63%
peak energy was around 31fpe before but it was behaving like an unregged gun unless i increased hammer weight or used lighter pellets which is another reason i wanted to try this
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Ah okay, a .25 cal. With the poppet being 8.1mm, you have lots of room to enlarge the throat.
it's a .25 so plugging your numbers we went from 56% to 63%
Meaning you drilled the throat to approx 5.87mm (0.231")?
Bear in mind the larger throat will make the valve harder to knock open, meaning it will need more hammer strike to realize the power potential. Various ways available to accomplish that...more hammer spring tension or a heavier hammer spring or a heavier hammer, or more stroke, or a harder poppet material, or some combination thereof.
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Ah okay, a .25 cal. With the poppet being 8.1mm, you have lots of room to enlarge the throat.
it's a .25 so plugging your numbers we went from 56% to 63%
Meaning you drilled the throat to approx 5.87mm (0.231")?
Bear in mind the larger throat will make the valve harder to knock open, meaning it will need more hammer strike to realize the power potential. Various ways available to accomplish that...more hammer spring tension or a heavier hammer spring or a heavier hammer, or more stroke, or a harder poppet material, or some combination thereof.
woops that's the diameter 63%
in area we went from ~30>40% roughly
ports 4mm throat 5mm
I'm filling it right now it's holding air at 100bar, 50 more pumps to go
edit: forgot to mention i did a bit of deburring with the smooth part of a cobalt drill bit and fine silicon carbide paste inside the valve
drilled with the same drill bit and vaseline, the valve is a very weak material "luckily"
it's not perfect and i didn't care to polish the other parts but let's see how it goes
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it went horrible :D
shot a long string to 100bar to compare with a string i did before, it's close to what i was seeing before but less consistent
used 2 chrony's to reduce error
it's using about 10 percent more air now but where's it going?
next i will add hammer weight to "flatten the curve"
then test with a lower reg setting...on another day
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I look forward to seeing more testing.
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forgot to mention that i measured plenum volume by filling that middle part in the pic w/ water and weighing, it came at a measly ~3.8ml
gonna take a measurement of cylinder volume next time
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my new swaging die arrived and i went to smash some bullets
both the storm and R8 barrels had a hard time with the other die(about a mm larger)
this one makes prettier bullets with a longer angled part smaller meplat, more like HN slugs AND they go smoothly in and out of the storm barrel just about perfect fit will test tomorrow
time to shot some groups
the R8 was spitting the older bullets at 964fps @43.5gn for 90fpe
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I'm curious about this R8
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&^^& I forgot to measure the hole behind the poppet spring, that must be bottlenecking everything
I'm curious about this R8
it's an air hog the way it came i get 8 shots at same power level than it declines
will detune to 5% below the knee once i find a spring with 1.7mm wire
there is a reg for it but I don't see the point on a semiauto
the other day i blew up the plastic moderator on it shooting oversized slugs
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did u try to turn that regulator screw ? i was planning to try, but idk which way it inceases and decreases ;D if it's like that aftermarket regulator then it should be counterclockwise to incease power if i remem right?
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did u try to turn that regulator screw ? i was planning to try, but idk which way it inceases and decreases ;D if it's like that aftermarket regulator then it should be counterclockwise to incease power if i remem right?
i`ll get a power tune dialed first
yeah that's right from reports on the internet, how much to turn tho i have no idea
and @$%^ got even weirder now, added 2.2g in form of a lead disc to the(32g) hammer and it's using less air(38 shots to 100bar vs 30) see the attachment
before porting this thing i'd invert the hammer spring guide which weighs 4g and get 13 shots on reg then fall
edit: which of these bits i should use for polishing the ports?
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I wonder that hammer weight too and think about adding weight for stock hammer a bit then probably shorter spring which has about 2mm gap to valve(this would be ffh?.) Idk should it work but it would be really easy to test one.
Btw ur not regged atm in that graph?
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I wonder that hammer weight too and think about adding weight for stock hammer a bit then probably shorter spring which has about 2mm gap to valve(this would be ffh?.) Idk should it work but it would be really easy to test one.
Btw ur not regged atm in that graph?
yes it is "regged" believe it or not, with a stunning 4cc plenum
i did shot a "before" porting string but the chrony missed many shots, it started at 613fps peaked at 663 with some anomalies at both ends, i thought it was so bad i didn't mind to redo all 30 shots but now it's worse lol
what i conclude is that this thing needs stroke more than strike/momentum but let me confirm it later after checking the plenum hole i missed
like nervoutrigger said it's better to constrict the flow at the end so that little hole is suspicious
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As far as those bits go if they are diamond ones, I use those to open ports , polishing I do with compounds and felt. If I get what you are up to.
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As far as those bits go if they are diamond ones, I use those to open ports , polishing I do with compounds and felt. If I get what you are up to.
sorry, i meant to shape the ports
they are "xainamond"
i was thinking of using the conical(straight ones?) on TP downside and maybe the round ball on the top, barrel and valve I'm not sure
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Which bits you use are not as important as not allowing them to contact areas that are to remain uncut. Ask which bit would help reach the areas you want to address, without any oopses, and you have your answer. Controlling the tool is more important than cutting speed.
I prefer an abrasive filled rubber bit or bob: https://www.mcmaster.com/abrasive-bits/rubber-cushioned-abrasive-grinding-bits-for-metals-8/ (https://www.mcmaster.com/abrasive-bits/rubber-cushioned-abrasive-grinding-bits-for-metals-8/)
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I use this type of bit for light material boring and milling with a small drill press and multi vice. along with other burr bits etc. yup :)
(https://www.gatewaytoairguns.org/GTA/index.php?action=dlattach;topic=205566.0;attach=424305;image)
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Drill press helps control the bit. Good plan.
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Which bits you use are not as important as not allowing them to contact areas that are to remain uncut. Ask which bit would help reach the areas you want to address, without any oopses, and you have your answer. Controlling the tool is more important than cutting speed.
I prefer an abrasive filled rubber bit or bob: https://www.mcmaster.com/abrasive-bits/rubber-cushioned-abrasive-grinding-bits-for-metals-8/ (https://www.mcmaster.com/abrasive-bits/rubber-cushioned-abrasive-grinding-bits-for-metals-8/)
sure i mean just a little touch to help air flow
how are the shroud designs going? i was going to ask if you have made one for the stormrider?? a 20mm ID tube over 12mm barrel would be too tight to redirect the air?
I use this type of bit for light material boring and milling with a small drill press and multi vice. along with other burr bits etc. yup :)
(https://www.gatewaytoairguns.org/GTA/index.php?action=dlattach;topic=205566.0;attach=424305;image)
could use a dewalt hand drill or dremel but no drill press at the moment
how much to turn tho i have no idea
someone mentioned in a video that it's 20bar per full turn
edit: 40bar
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Baco,
I would use a need file, slowly and very carefully. Sure power tools are faster, if you have many jobs to do and have had lots of practice. The diamond burr is probably less likely to go skidding off where you don't want it to cut, because you don't have to push as hard to make it cut as with a conventional burr. So, I understand the purpose. Only you can judge your skill level.
I see the Stormrider shroud as a great idea. A 4 mm radial gap between barrel and shroud ID is a bit small. Probably can't go much larger than that before the shroud contacts the air tube. If you are frisky, you could take a larger tube and press a clearance channel along its length - or at least over the air tube. It all depends on how much work you want to put into it.
A skilled welder could cut the clearance, then well in a strip of tube to close the shroud up again.
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I am also looking at adding a shroud to my SR rifles in 17/22 cal,
here is some info that may help,
Bbl Dia = .475",
Distance between bbl and air tube = .165"
A very close fit for a .750" dia thin walled shroud tube,
is about max diameter to fit.
Action width at the air tube = .790"
Shroud length = 22/24" max length.
Also thinking of adding a Howitzer type of air stripper
and have the exhaust flow back into/thru the shroud,
and exit at the back of the shroud.
Same design as I just finished on the QB Starling Sniper rifle
for enforcing the "No Fly" around the cluck cluck field.
Very Quite now = a 3+ bird Quite
I can now get 3 Bandits before they get wise,
was only a 1 bird quite before.
The major headache now is finding 3/4" O/S diameter thin walled tubing
with a wall thickness of .035" to .062" thick.
Tia,
Don
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I would be thrilled if someone were to figure out an easy hollow shroud. I have a piece of 16x12mm CF tube around my barrel forward of the OEM barrel band, which puts tension on the barrel when the LDC is threaded against it. I would ditch the factory barrel band and moderator for a good shroud setup, especially one that makes it as quiet as the factory LDC.
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dismantled the thing again to redo my half @@@ job
first checked the plenum hole = 5mm, opened to 5.5 then 6mm, the spring is 6.5mm ID so there's just enough material
i tried to open the reg internals to check any issue but after 33 turns it didn't want to come apart(the threads were clicking for some 20 turns already) and now i'm not sure what it's set
proceeded to angle the TP and ports i could reach, just a milimeter or so
polished the holes with a felt bit and a cotton swab attached to a dremel, the cotton swab worked great on the brass TP
cleaned the barrel and maintube with paper towels, main tube volume is ~100c after accounting for the reg/valve, bigger than i expected
assembled everything praying for the regulator gods to not bully me
put a 15x2mm n70 oring on the valve face a la bstaley but it's contacting a ridge that holds the valve so i better check it later soon
i removed the weight from the hammer and that's it, it is using very little air per shot i estimate 10% less than stock AND there's still frigging air coming out of the breech lol
what could be wrong with this thing
30.4gn string:
574
569
564
555
579
578
577
579
585
569
miss
519
miss
miss
611
598
595
601
598
618
603
607
663
611
595
618
633
611
623
645
628
620
miss
601
601
584
571
548
539
i'll interpolate misses to not break the graph
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i inverted the hammer spring guide to increase weight without reducing the stroke and did a new string, the 2 lowest ones i forgot to lock the bolt and it shoot all the way back, that's a new one:
554
552
562
563
560
559
574
514
562
511
549
569
572
562
577
578
578
588
590
581
582
590
603
609
611
miss
630
638
643
656
656
647
635
633
617
575
585
552
552
i'll interpolate the 2 missfires and 1 miss for the graph
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where would you say the reg is set on this mess?
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Did you check tube pressure when those higher velocity results came up? I would guess the reg is probably not doing anything at this point. The shot string looks pretty close to an unregulated setup and I would bet you hit peak velocity around 150-160b indicated.
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Did you check tube pressure when those higher velocity results came up? I would guess the reg is probably not doing anything at this point. The shot string looks pretty close to an unregulated setup and I would bet you hit peak velocity around 150-160b indicated.
yes, i noted the pressure 7 times, on the graph i attached you can check the pressure that the spreadsheet interpolates at the right side, it peaked at 1750psi but as we're well below the "knee" there's a confusing factor which is a rise when it comes off reg, i know the reg "works" cause last week i shot it with the hammer guide mod and it shot a tight 13 shot string(27gn slugs @ 712fps to 150bar then fell as is usual)
https://hardairmagazine.com/ham-columns/tuning-regulated-pcp-airguns/
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The rising velocity at the end is the tell-tale sign that the hammer strike is insufficient for the current setpoint (or the setpoint is too high for the hammer strike, whichever way you prefer to think of it).
Peak velocity is occurring ~1750psi and all I can say for sure is the regulator setpoint is somewhere north of there...maybe 2200psi if I had to guess. If you want to home in on it experimentally, use an excess of hammer strike so it's operating up on the velocity plateau. The pressure at which the velocity begins to taper off is a good approximation of the setpoint.
If your goal is shot count over velocity & energy, reduce the setpoint. If your goal is more velocity and energy over shot count, add more hammer strike....more hammer spring preload or a heavier spring or more hammer stroke or some combination thereof.
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The rising velocity at the end is the tell-tale sign that the hammer strike is insufficient for the current setpoint (or the setpoint is too high for the hammer strike, whichever way you prefer to think of it).
Peak velocity is occurring ~1750psi and all I can say for sure is the regulator setpoint is somewhere north of there...maybe 2200psi if I had to guess. If you want to home in on it experimentally, use an excess of hammer strike so it's operating up on the velocity plateau. The pressure at which the velocity begins to taper off is a good approximation of the setpoint.
If your goal is shot count over velocity & energy, reduce the setpoint. If your goal is more velocity and energy over shot count, add more hammer strike....more hammer spring preload or a heavier spring or more hammer stroke or some combination thereof.
there's one last thing i wanna try which is a lighter pellet, not sure why but the heavier i go the more it looks like the hammer is not enough
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there's one last thing i wanna try which is a lighter pellet, not sure why but the heavier i go the more it looks like the hammer is not enough
Yes that is the expected result. Heavier pellets take longer to accelerate so they benefit from the valve being open longer. So in a scenario where there is insufficient hammer strike, heavier pellets will suffer disproportionately.
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Wes is the man to help. He's got mine running around 22 fpe with a 100 bar reg setting.
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Wes is the man to help. He's got mine running around 22 fpe with a 100 bar reg setting.
Is that with the 25 cal? I'm impressed by the huge increase in efficiency by going to 25 cal.
I just tried pushing a .249" NSA slug through both my 9" and 16" barrels and both had ridiculously tight muzzles. The 16" barrel swaged the slug down to .248" or smaller and the rifling engraving was almost flush with the body of the slug! In fact it was so tight I cut myself on the breech when the slug finally popped out. FTT's were also tight in both barrels. I'm emailing Wes to see if this is normal, because I don't think it is. The bores seemed fine otherwise, maybe a few rough spots in the 16" aside from the muzzle. I wanted to see how the .249's went through the barrel to see if they would be worth testing, but now I don't think so. I think this explains the bad accuracy I get past 50'.
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i removed the "bstaley" and shot a string again but the chrony decided to reset at the end of the 4th mag :o
shot to shot consistency improved a LOT, the spread overall(+-16%) is not good, it's peaking at 682fps on shot 24
valve porting increased the force needed to open valve too much for the poor hammer even with extra weight
so next thing to do is lower the reg just a bit till i can get 5% ES with the stock hammer/spring
Wes is the man to help. He's got mine running around 22 fpe with a 100 bar reg setting.
i believe we're getting there soon
there's one last thing i wanna try which is a lighter pellet, not sure why but the heavier i go the more it looks like the hammer is not enough
Yes that is the expected result. Heavier pellets take longer to accelerate so they benefit from the valve being open longer. So in a scenario where there is insufficient hammer strike, heavier pellets will suffer disproportionately.
yeah exactly what i was seeing in practice, and that is now aggravated with the porting
Wes is the man to help. He's got mine running around 22 fpe with a 100 bar reg setting.
Is that with the 25 cal? I'm impressed by the huge increase in efficiency by going to 25 cal.
I just tried pushing a .249" NSA slug through both my 9" and 16" barrels and both had ridiculously tight muzzles. The 16" barrel swaged the slug down to .248" or smaller and the rifling engraving was almost flush with the body of the slug! In fact it was so tight I cut myself on the breech when the slug finally popped out. FTT's were also tight in both barrels. I'm emailing Wes to see if this is normal, because I don't think it is. The bores seemed fine otherwise, maybe a few rough spots in the 16" aside from the muzzle. I wanted to see how the .249's went through the barrel to see if they would be worth testing, but now I don't think so. I think this explains the bad accuracy I get past 50'.
the barrel Wes sent me the 6.35mm slugs were like you described, the 6.34mm go down easy but some ppl say you need them sized to contact groove diameter so idk what to say
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Wes is the man to help. He's got mine running around 22 fpe with a 100 bar reg setting.
Is that with the 25 cal? I'm impressed by the huge increase in efficiency by going to 25 cal.
I just tried pushing a .249" NSA slug through both my 9" and 16" barrels and both had ridiculously tight muzzles. The 16" barrel swaged the slug down to .248" or smaller and the rifling engraving was almost flush with the body of the slug! In fact it was so tight I cut myself on the breech when the slug finally popped out. FTT's were also tight in both barrels. I'm emailing Wes to see if this is normal, because I don't think it is. The bores seemed fine otherwise, maybe a few rough spots in the 16" aside from the muzzle. I wanted to see how the .249's went through the barrel to see if they would be worth testing, but now I don't think so. I think this explains the bad accuracy I get past 50'.
It is the .25. He did an amazing job on it in my opinion. 28 shots at around 22 fpe from that little tube. I haven't slugged my barrel, but it seems to shoot everything well.
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i removed the "bstaley" and shot a string again but the chrony decided to reset at the end of the 4th mag :o
shot to shot consistency improved a LOT, the spread overall(+-16%) is not good, it's peaking at 682fps on shot 24
valve porting increased the force needed to open valve too much for the poor hammer even with extra weight
so next thing to do is lower the reg just a bit till i can get 5% ES with the stock hammer/spring
Wes is the man to help. He's got mine running around 22 fpe with a 100 bar reg setting.
i believe we're getting there soon
there's one last thing i wanna try which is a lighter pellet, not sure why but the heavier i go the more it looks like the hammer is not enough
Yes that is the expected result. Heavier pellets take longer to accelerate so they benefit from the valve being open longer. So in a scenario where there is insufficient hammer strike, heavier pellets will suffer disproportionately.
yeah exactly what i was seeing in practice, and that is now aggravated with the porting
Wes is the man to help. He's got mine running around 22 fpe with a 100 bar reg setting.
Is that with the 25 cal? I'm impressed by the huge increase in efficiency by going to 25 cal.
I just tried pushing a .249" NSA slug through both my 9" and 16" barrels and both had ridiculously tight muzzles. The 16" barrel swaged the slug down to .248" or smaller and the rifling engraving was almost flush with the body of the slug! In fact it was so tight I cut myself on the breech when the slug finally popped out. FTT's were also tight in both barrels. I'm emailing Wes to see if this is normal, because I don't think it is. The bores seemed fine otherwise, maybe a few rough spots in the 16" aside from the muzzle. I wanted to see how the .249's went through the barrel to see if they would be worth testing, but now I don't think so. I think this explains the bad accuracy I get past 50'.
the barrel Wes sent me the 6.35mm slugs were like you described, the 6.34mm go down easy but some ppl say you need them sized to contact groove diameter so idk what to say
My bores are only tight right at the muzzle, and one of the barrels swaged the slug until the difference in the rifling impressions and the body of the slug were almost nonexistent. I think both muzzles are too tight, tighter than a choke should be. Even with pellets I have great difficulty getting them out of the bore. My 177 barrel that shoots perfect is smooth as silk the whole way down. I sent Wes an email and asked what there is to be done.
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My bores are only tight right at the muzzle, and one of the barrels swaged the slug until the difference in the rifling impressions and the body of the slug were almost nonexistent. I think both muzzles are too tight, tighter than a choke should be. Even with pellets I have great difficulty getting them out of the bore. My 177 barrel that shoots perfect is smooth as silk the whole way down. I sent Wes an email and asked what there is to be done.
I guess I've been lucky with all of mine. None of them seem to be fussy about ammo. I've never slugged any of them that I remember.
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My bores are only tight right at the muzzle
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I think both muzzles are too tight, tighter than a choke should be.
Correct me if I'm wrong but it sounds like you are distinguishing these tight spots as different from a choke...a choke being a tight region that is usually 1/2" long or more. A spot that feels tight right at the muzzle is usually the result of a burr left behind from crowning. If so, the good news is that's usually a pretty easy fix with a brass screw and abrasive compound.
SPA's reputation for mangling crowns precedes them so it would not surprise me in the least.
The other clue for me is where you said:
one of the barrels swaged the slug until the difference in the rifling impressions and the body of the slug were almost nonexistent.
suggesting the burr may be wiping out the profile of the lands and grooves as the slug emerges from the muzzle.
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What is the air tube outside diameter on the Stormrider? Looks to be around 25 mm or 1".
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What is the air tube outside diameter on the Stormrider? Looks to be around 25 mm or 1".
For what it's worth, a Huma plenum for a Disco fits in the tube. I am 90% certain it's the same dimensions as the Disco.
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My bores are only tight right at the muzzle
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I think both muzzles are too tight, tighter than a choke should be.
Correct me if I'm wrong but it sounds like you are distinguishing these tight spots as different from a choke...a choke being a tight region that is usually 1/2" long or more. A spot that feels tight right at the muzzle is usually the result of a burr left behind from crowning. If so, the good news is that's usually a pretty easy fix with a brass screw and abrasive compound.
SPA's reputation for mangling crowns precedes them so it would not surprise me in the least.
The other clue for me is where you said:
one of the barrels swaged the slug until the difference in the rifling impressions and the body of the slug were almost nonexistent.
suggesting the burr may be wiping out the profile of the lands and grooves as the slug emerges from the muzzle.
The barrel with the sight is my 16" barrel, which is much tighter. The other barrel is 9" long, and smoother at the crown. The chatter marks are from having to hit the slug a few times with the rod to push it out. The pic with just the slugs are from pushing them through, with much difficulty, without slamming them with the rod.
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you can paint them with a marker to better see if there's groove contact
mine looked like that too, the .25 ones
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Peter
The O/S diameter of my 17 cal SR measures right around .868", filled to 2900 psi. HTH's
Don
What is the air tube outside diameter on the Stormrider? Looks to be around 25 mm or 1".
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screwed the reg clockwise 3/4 of a turn
it seems to be using more air till shot 11 then it stabilizes
edit: the shpreadsheet is not interpolating correctly so i'll paste the string
620.0712 197 bar
610.2288
620.0712
629.9136
620.0712
616.7904
639.756
634.17864
623.352
634.8348 155 bar
644.6772 150
658.78464
633.1944
666.0024
664.69008
472.4352 132
648.61416 130
661.0812
636.4752
646.97376
608.91648 115
608.91648
600.3864 110
577.4208
561.0168
561.0168 101
538.0512
508.524 98
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1/4 turn more, so 1 turn total
489 2900
472
479
466
486
486
489 2610
492
492
482 2510
509
479
486
487
479
469 2320
469
466
495
490
495
497
465
501 2030
509
504
506
518 1885
518
525
535 1740
552
625
617 1595
600
574
563
543
543 1450
i'm lost, now there's a flat string but the hammer still can't open the valve fully
reg feels like it's not going to move more clockwise
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Peter
The O/S diameter of my 17 cal SR measures right around .868", filled to 2900 psi. HTH's
Thanks, Don
The reason for asking is to lay out a potential shroud design. I started based on my incorrect assumption, making the shroud OD the same as the air tube OD. It may look funny with a larger shroud OD than air tank. Yes, there is tube to tube inference, but there is an app for that :)
That design will have to wait, as another has taken priority.
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ok I'll test one more reg setting and then am done with these pellets, they were oversized and i noticed a ring near the choke like it's cutting there
storm tube
your guess is right and there's around 5.5mm clearance between barrel and maintube, but would need a new barrel band too, i may have the file somewhere remind me to check tomorrow
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storm tube
your guess is right and there's around 5.5mm clearance between barrel and maintube, but would need a new barrel band too, i may have the file somewhere remind me to check tomorrow
Actually it's 22mm OD and more like 5mm clearance
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turned it back 1/2 turn counter-clockwise and now it seems to be opening the "dang" valve, in reality i'm not sure if that was happening on the last string or just a strange reg creep
here are the results:
(https://i.postimg.cc/YCCN02Gr/Screenshot-122.png)
if we take out the 2 outliers there's a good string with 17 shots under 4% ES
(https://i.postimg.cc/RZp7HrKc/Screenshot-123.png)
here the string with real(measured) pressure
604 2900
676
669
652
663
654
652 2510
654
650
633
598 2320
712
630 2220
656 2162
541 2132
650 2060
650 2016
663
652
647 1870
656
652
650
636
611 1610
598
582
563 1493
this is not very far from the power level it was before porting the difference is now the "shootable" range almost doubled
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A smidge less hammer spring should even that out IMO. No???
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A smidge less hammer spring should even that out IMO. No???
i have spare springs i may play with, also noticed that putting a piece of lead in the hammer on the previous reg setting decreased ES by 10fps or so
new string with the 6.34mm 25gn slugs, i guess the reg is around 120bar??
(https://i.postimg.cc/52ffY3zJ/Screenshot-125.png)
let me say that the magazine didn't like these little slugs and chewed a bunch of them
i don't understand this drop at shot 12 on all strings
686 2900
684
680
684
686
674
676 2465
673
684
684
684 2320
638
643 2175
miss
667
670
686
700
698
696 1870
676
663 1740
659
654
640 1600
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Maybe the reg has a slow recovery time?
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Maybe the reg has a slow recovery time?
on the few fast shots given i didn't notice a drop in velocity, I'm suspecting some oring inside the washer stack because 1)the reg valve body had an oversized oring, 2) the screw didn't come out
but if I try open it now i risk losing the setting again 😃
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Albeit a non reg Gen 1, i guess it still applies.
(https://i.postimg.cc/QdV8hjGF/80.jpg)
Diffusor. This the 1st design of mine, the later one used oval shaped openings on a in total longer shroud. Same same..
(https://i.postimg.cc/MHZ5NPM8/78.jpg)
Out rear i just cut me a "sealing adapter" that was a reasonably tight fit vs the shroud. The entire thing held in as it bottomed out between the diffusor up front and the receiver.
(https://i.postimg.cc/JhZGCRZb/81.jpg)
Thin wall alu tubing. Just a piece i scavenged off of a microphone stand :o . Works as well as anything else i guess.
(https://i.postimg.cc/Kjqn3m91/82.jpg)
Uhu. Sports a home brew mod too. All in all a rather quiet proposition IMO. Goes a very modest "thud" at approx 90J using 25,4´s in 22cal. 25,4´s in 25.. well..
(https://i.postimg.cc/s2JWNy6f/86.jpg)
Regular Knock Outs used. Accuracy isn´t stellar but way above average. Barrel on this one does sport a choke, but rather less pronounced.
Shoots hard seeing what it is.
(https://i.postimg.cc/QdwYdghK/85.jpg)
LabRadar doesn´t lie. Started there and kept climbing. Coming to a rest at approx 1040-1050 approx.
(https://i.postimg.cc/d3tfKtk3/83.jpg)
Yes. An SSG. Uses a modified progressive dual setup, one of them being an Impact hammer spring. Works well albeit semi stiff to cock.
Did a spitting image kind of deal on a CP-2 recently. Same 22cal barrel length, just now as a PCP sporting an approx 300cc tank. Power about on par. The CP-2 and the Gen 1 Riders are deadringers within.
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do you need to boil linseed oil to get that finish? it's beautiful 😍
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Most Snowpeak/Artemis guns i've had through my hands using wood have all been literally drenched in plastic so called pore filler.
This is what hands them that rather pöastic feel.
Only reason for the doing it that way is that it's fast and thus cheap to produce en masse.
Only way i know to get rid of it is to sand the stuff down.
Done it to my Stormrider, P-15 and now my M-16.
Pore filler gone i use a slight amount of dye to get that hue.
Then, as you mention, a 50/50 mix of boiled linseed n turpentine.
At first i apply it wet for as long as the wood takes for it.
Then let it rest to cure. Yet another layer and this time i sand it too - lighter and lighter paper as I go.
Final stage ( not done in the pics) a layer of antique wax or similar that you buff out.
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Word of advice from a tech standpoint.
The valve on these guns are like made of soft friggin cheese.
As has been noted the "retainer screw" simply isn't enough to cope over time really. This in essence goes for the receiver vs tube too.
Thus it can be a very good idea to ad yet another such cap screw yo increase shear strength, and thereby load capacity by x2.
Me i got fed up with that &^^& material and made a couple of fresh valve housings out of a rather hard core material known as alumec (compare Titanic grade 6 approx).
Then again i friggin wear them threads out ripping into those guns on a regular basis.
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Most Snowpeak/Artemis guns i've had through my hands using wood have all been literally drenched in plastic so called pore filler.
This is what hands them that rather pöastic feel.
Only reason for the doing it that way is that it's fast and thus cheap to produce en masse.
Only way i know to get rid of it is to sand the stuff down.
Done it to my Stormrider, P-15 and now my M-16.
Pore filler gone i use a slight amount of dye to get that hue.
Then, as you mention, a 50/50 mix of boiled linseed n turpentine.
At first i apply it wet for as long as the wood takes for it.
Then let it rest to cure. Yet another layer and this time i sand it too - lighter and lighter paper as I go.
Final stage ( not done in the pics) a layer of antique wax or similar that you buff out.
when you say boiled linseed is it pure linseed oil boiled or some other additive mix?
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I just pick it up in a quart/liter bottle and then as boiled linseed oil.
I mix that 50/50 with turpentine, to make the linseed penetrate the wood easier.
A little goes a long way but truth be told at first it is a relatively heavy amount. The stock will tell how much it can "digest", and you´ll soon enough see where the linseed had been absorbed by the stock.
At first, to make the stuff soak up to its max just keep at it wet on wet. All stocks react different to this, just read what it tells. As you proceed you´ll notice at a given point that the stock doesn´t soak up as much of the stuff anymore. Then leave it be for a while.
Yes. Of course you can use the rifle meanwhile, hurts nothing. Just wipe it down after use. Leave it be for like 3+ weeks.. then apply the final coat-s and/or wax.
To hand you an idea what the finished product will be. This is approx 150yr old walnut that´s been just cleaned in depth and then treated per above.
(https://i.postimg.cc/QNTQxV31/87.jpg)
(https://i.postimg.cc/CxFkNNfs/89.jpg)
It´s an old Westley Richards so called Monkey tail. A blackpowder rifle in 45 caliber from approx the mid 1860´s. Linseed, oil sanding. Left to cure, more oil sanding and final layer coupled with buffing the thing out.
Stock is way better protected vs the elements as well as use while still feeling "all walnut" (for lack of better description)
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I just pick it up in a quart/liter bottle and then as boiled linseed oil.
I mix that 50/50 with turpentine, to make the linseed penetrate the wood easier.
A little goes a long way but truth be told at first it is a relatively heavy amount. The stock will tell how much it can "digest", and you´ll soon enough see where the linseed had been absorbed by the stock.
At first, to make the stuff soak up to its max just keep at it wet on wet. All stocks react different to this, just read what it tells. As you proceed you´ll notice at a given point that the stock doesn´t soak up as much of the stuff anymore. Then leave it be for a while.
Yes. Of course you can use the rifle meanwhile, hurts nothing. Just wipe it down after use. Leave it be for like 3+ weeks.. then apply the final coat-s and/or wax.
To hand you an idea what the finished product will be. This is approx 150yr old walnut that´s been just cleaned in depth and then treated per above.
(https://i.postimg.cc/QNTQxV31/87.jpg)
(https://i.postimg.cc/CxFkNNfs/89.jpg)
It´s an old Westley Richards so called Monkey tail. A blackpowder rifle in 45 caliber from approx the mid 1860´s. Linseed, oil sanding. Left to cure, more oil sanding and final layer coupled with buffing the thing out.
Stock is way better protected vs the elements as well as use while still feeling "all walnut" (for lack of better description)
let me see if i got it right:
sand coating off with 220 grit
apply BLO/turpentine 50/50 soaking in first few days
oil sanding during intervals(with pure BLO?)
finish with BLO/Wax (2:1?)
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Basically.
Just, you go finer and finer paper as you go for the last bit.
I usually stop at 800 or 1200 grit - all depending.
Then. BLO does need WEEKS to cure. So this takes a little while.. The "old" way of doing it i guess, but the end result speaks for itself IMO.
Many use different versions of pore filler these days. Some work better than others but if it´s that true "wooden feel" you want.. BLO or Danish oil or Tung oil does it.
At least that´s my findings.
One added BIG side benefit to this is that a BLO finish is quite simple to "repair". Just add the stuff and repeat per above... you´ll be fine.
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Basically.
Just, you go finer and finer paper as you go for the last bit.
I usually stop at 800 or 1200 grit - all depending.
Then. BLO does need WEEKS to cure. So this takes a little while.. The "old" way of doing it i guess, but the end result speaks for itself IMO.
Many use different versions of pore filler these days. Some work better than others but if it´s that true "wooden feel" you want.. BLO or Danish oil or Tung oil does it.
At least that´s my findings.
One added BIG side benefit to this is that a BLO finish is quite simple to "repair". Just add the stuff and repeat per above... you´ll be fine.
i see they use cobalt as a drying agent on BLO, when i boil the virgin linseed to 240c i might just drop a cobalt drill bit in the pot to reduce drying times 🤔😆
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i did shot half a dozen strings since my last post so i`ll try to shorten this one
i had added a 2.2g lead disc to the hammer and a spring guide cap slightly shorter to balance the preload
this is the result with 25 and 28 grain slugs
shots / ES
25gn: 14 <4%ES, 8 <2%ES
28gn: 15 <4%ES, 11 <2%ES
(https://i.postimg.cc/pWvwK93R/Screenshot-129.png)
and this is the poor man`s plenum extender:
(https://i.postimg.cc/mgqQBs4r/photo-2023-02-20-20-19-39.jpg)
i fitted 8 orings around the threads on this thing, which increased the plenum by ~1cc or 20%(whoa)
it's a prototype(don't do this at home ppl)
energy increased and shot count decreased proportionally
shots / ES
24.8gn: 12 <4%ES, 4 <2%ES
28.3gn: 11 <4%ES, 6 <2%ES
(https://i.postimg.cc/L9bLPP0b/Screenshot-130.png)
also tested pellet base slugs at 21/22gn it's close to 800fps/30fpe
then i added one extra gram to the hammer and took -3mm off the spring cap
shots / ES
24.8gn: 15 <4%ES, 4 <2%ES
28.3gn: 12 <4%ES, 7 <1%ES
(https://i.postimg.cc/vZ4dcp1j/Screenshot-131.png)
pic of the spring caps https://i.postimg.cc/Jztbfh9g/photo-2023-02-20-20-19-39-2.jpg (https://i.postimg.cc/Jztbfh9g/photo-2023-02-20-20-19-39-2.jpg), https://i.postimg.cc/J4pNYXdZ/photo-2023-02-20-20-19-38.jpg
the aberrations around shot 8-12 seem to be fixed on the middle setup by balancing the hammer strike with valve/plenum pressure(Thanks James) i think a bit more preload will get things right
(https://i.postimg.cc/J4bJH4gD/Screenshot-133.png)
(https://i.postimg.cc/L4Tdvjrm/Screenshot-134.png)
i'm not sure does increased plenum volume increases force needed to open the poppet?
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the new barrel oring is a success leak is gone power increased ~10% with the 25gn's, i'm expecting 35fpe with the 28gn's
still a couple shots dropping but i'll change the hammer to see what happens
reg appears to be at 127bar
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Your reg might also need to be turned down just a touch. My Altaros doesn't like to be set at the absolute max. Even just turned back a touch was enough to smooth things out. Might also try waiting for a bit between shots to let the reg refresh. If I shoot as fast as possible I get some low velocities with the tiny plenum I'm using. Speaking of, I owe some photos of my regulator stuff.
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This might be relevant to your shot string issues: https://www.gatewaytoairguns.org/GTA/index.php?topic=206422.0;topicseen (https://www.gatewaytoairguns.org/GTA/index.php?topic=206422.0;topicseen)
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i tried to open the reg a bit without taking it out of the gun but it unscrewed the body together and now it's leaking, will leave it for another day
before that i shoot 3 strings with different hammer settings and can confirm the hammer is maxed out for this reg setting
DJ thanks for the recommendation will take a look
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while fighting the leak i noticed something obvious but cool
the poppet spring is under preload and by varying the plenum space with orings on the valve side you can tune this, i left 4 orings there and the spring weight needed to open the valve decreased 1.2 > 0.2kg
which means less hammer is needed BUT idk about shot to shot consistency, i imagine at lower reg pressures it'll be ok
i took out the orings from the reg side it seems the leak was coming from there
also this thing popped out without me unscrewing anything
nothing seems wrong with this one
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Some of you guys were interested in a shroud/muffler for the Stormrider. Mike asked me to design a reflex LDC for his modified Diana Chaser, that shares some parts with the Stormrider. Both have challenges, because their barrels are mounted so close to the air tube.
The project is in its early stages, but you might be interested in this thread:
https://www.gatewaytoairguns.org/GTA/index.php?topic=209016.msg156461281#msg156461281 (https://www.gatewaytoairguns.org/GTA/index.php?topic=209016.msg156461281#msg156461281)