GTA
All Springer/NP/PCP Air Gun Discussion General => PCP/CO2/HPA Air Gun Gates "The Darkside" => Topic started by: Ribbonstone on October 18, 2017, 07:55:48 PM
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BEst effort with a .22 Beeman Chief.
YEp...did do some adjustments to this Cheap(est) Chinese PCP.
1. Adjusted the trigger.
2. Polished the barrel throat (mostly to keep if from chewing up the itty-bitty bolt probe o-ring).
3. Adsjusted the mainsprig length/tension to get it running "right" at 2K.
4. Moved the barrel band back until it was inletted into the stock to stablize.
Can see the "why" of that in these posts:
https://www.gatewaytoairguns.org/GTA/index.php?topic=133513.0 (https://www.gatewaytoairguns.org/GTA/index.php?topic=133513.0)
And you can read about my thoughts on regulation in these posts:
https://www.gatewaytoairguns.org/GTA/index.php?topic=133350.0 (https://www.gatewaytoairguns.org/GTA/index.php?topic=133350.0)
So I filled her up to 2K and got the scope just about dead on at 40 yards.
Groups sucked.
Realized it had beeen maybe 200 shots from the last barrel cleaning.
Detached the LDC and cleaned (carefully) form the muzzle with a rod. Damp patch/3 dry patches...repeated that 3 times.
OK...it was FILTHY...which indicates either a need for lubed pellets of cleaning every 100 shots (about 4 fill ups).
Refilled the rifle to 2K (to get the full shot count) and tried 25 shots at 40yards.
(http://i157.photobucket.com/albums/t50/ribbonstone/chief/17256d96-8ec2-49b5-b9ad-3f5f12782d29.jpg) (http://s157.photobucket.com/user/ribbonstone/media/chief/17256d96-8ec2-49b5-b9ad-3f5f12782d29.jpg.html)
SOOOoooo... I do NOT think it's going to be a 25 shot/ 25 foot pound rifle fot +40 yards on tiny-critters...that last 5-shot group showed TOO MUCH vertical. Would make a good 20-22 shot rifle out to 40-50yards, and considering the amount of air used, a pretty efficient one.
IF (and this is just a suspicion at this point) I seriously thing of it as a 60 yard rifle, then I'll likely also think of it as a 15 shot rifle (thinking that shots #6-#21 would be in that stability range)....but all in all, I won't be thinking of any other changes than limiting myself to that pressure range/shot count.
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Great groups! Even the last set grouped well though they were a little lower. Nice!
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OH...did forget...added a Rocker1 LDC. Would be best to email him the actual diameter of the barrel, as these barrels do seem to vary a bit in diameter.
Partly luck....wife was out, so I could et up INSIDE and shoot out the back door...wind was calm enough to let smoke rise nearly vertically....and the rifle didn't show a "glitch"....which every test went as easy.
Right now...am thinking I'll:
1. Keep it unregulated.
2. Clean it at the 4th fill up (about 90-120 shots)
3. Pretty well keep it to 50yards or less (which kind of suits the scope/power level/trajectory)
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Always great when a plan comes together!
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Great info. Very nice groups. I haven't tried yet but was wondering about lighter pellets ie: 13-15 grain
Would they be more or less efficient? PCP's are new to me and still figuring it all out. I prefer 18 - 22 gr but was just wondering out loud.
Dave
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Less efficient in my trials. Not too far off the shot count (maybe 1- 2 fewer inside the same velocity variation) but less energy for the air used. Can get to about 900fps with 13.5gr. (24.3 foot pounds), but that's a little less energy than the 18gr. @ 785fps (24.6 foot pounds) for maybe one or two fewer shots (21 vs 23 shots).
May be worth it....have to see....if you aren't interested in long range shooting (lets say +50yards), it might be that the lighter pellets (even with their lower BC) fill your needs better than the heavy weights (with their higher BC's).
BUt..so far...the 18gr. AA's/18.1gr. JSB's and the 21gr. H&N's have shot the smallest groups.....so I kind of traded off all the "little stuff" over 50 yards for the more accurate pellet (in this particular barrel...your barrel could completely reverse the process).
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Less efficient in my trials. Not too far off the shot count (maybe 1- 2 fewer inside the same velocity variation) but less energy for the air used. Can get to about 900fps with 13.5gr. (24.3 foot pounds), but that's a little less energy than the 18gr. @ 785fps (24.6 foot pounds) for maybe one or two fewer shots (21 vs 23 shots).
May be worth it....have to see....if you aren't interested in long range shooting (lets say +50yards), it might be that the lighter pellets (even with their lower BC) fill your needs better than the heavy weights (with their higher BC's).
BUt..so far...the 18gr. AA's/18.1gr. JSB's and the 21gr. H&N's have shot the smallest groups.....so I kind of traded off all the "little stuff" over 50 yards for the more accurate pellet (in this particular barrel...your barrel could completely reverse the process).
Thanks for the info. I completely agree with you about the more accurate pellet. Always more important. I have been able to get like .3" - .5" groups with 18.13 gr JSB at 30 yrd. (haven't stretched it out yet for groups) I do have some 21 gr H&N that my Gamo Magnum really likes. I will give those a try on the weekend.
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OH...did forget...added a Rocker1 LDC. Would be best to email him the actual diameter of the barrel, as these barrels do seem to vary a bit in diameter.
I can testify to that because that the problem I had. I subsequently did a fit a trial by error. I must say it really quiets it down to the point that the smack is loader than the sending the pellet down the barrel.
The combo of the carbon fiber tube with the aluminum looks sharp.
Accuracy is a dime size group at 40 yards using CHP. That's what it liking so far with less than 500 pellets so far.
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I've tried a home-brew, a discontinued LDC (which looked great, a TKO,and a Rocker 1. Rocker 1 is a bit bigger, but works enough better that it's what I've stuck with. Chief isn't a "dainty" rifle, do the larger (but lighter) Rocker 1 seemed a good pick.
What I think is that the Chief suffers from variable barrel diameters (as do QB's)....so I really can't tell you what the actual size of your Chief barrel will be...something between 14.05mm and 14.15mm....but that difference makes a world of difference to how a snuggle-on/set screw lock-down LDC fits.
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OH...did forget...added a Rocker1 LDC. Would be best to email him the actual diameter of the barrel, as these barrels do seem to vary a bit in diameter.
I can testify to that because that the problem I had. I subsequently did a fit a trial by error. I must say it really quiets it down to the point that the smack is loader than the sending the pellet down the barrel.
The combo of the carbon fiber tube with the aluminum looks sharp.
Accuracy is a dime size group at 40 yards using CHP. That's what it liking so far with less than 500 pellets so far.
Nice! Sadly LDC of any kind are illegal in Canada (even for an air rifle >:( :P )
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Well...that kind of simplifies things....they're all going to be kind of loud.
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Lol!! Yep, that's the truth!
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Even without the LCD, the Chief is a very attractive rifle to own due to it`s bang for the buck factor and precision after some love.
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Yes I would agree. It is a very nice rifle. I just discovered that the one I have has a hollow threaded insert in rear which you can use to increase or decrease hammer spring pressure. A very nice and unexpected surprise I must say!
Dave
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Yes I would agree. It is a very nice rifle. I just discovered that the one I have has a hollow threaded insert in rear which you can use to increase or decrease hammer spring pressure. A very nice and unexpected surprise I must say!
Dave
How can you tell if it's for degaser or hammer spring adjuster ?
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Yes I would agree. It is a very nice rifle. I just discovered that the one I have has a hollow threaded insert in rear which you can use to increase or decrease hammer spring pressure. A very nice and unexpected surprise I must say!
Dave
How can you tell if it's for degaser or hammer spring adjuster ?
It comes with a degas tool that passes through the 5mm portion of threaded piece that sits against hammer spring. The degas tool uses the same threads but at rearmost portion. I used a 5mm allen wrench and turned in and could feel the increase in spring pressure.
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That's great news! Makes things a little simpler for guys, though I suppose you may still have to cut the spring initially if the power adjuster was already turned out all the way from the factory and you are still getting a descending string.
If I didn't already have a qb78 pcp conversion, I'd definitely want one of these! Would probably have cost less in the long run, though I sure have learned a whole lot, converting mine myself. That in itself has made my QB priceless, lol!
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Yes I would agree. It is a very nice rifle. I just discovered that the one I have has a hollow threaded insert in rear which you can use to increase or decrease hammer spring pressure. A very nice and unexpected surprise I must say!
Dave
How can you tell if it's for degaser or hammer spring adjuster ?
It comes with a degas tool that passes through the 5mm portion of threaded piece that sits against hammer spring. The degas tool uses the same threads but at rearmost portion. I used a 5mm allen wrench and turned in and could feel the increase in spring pressure.
I don't have a 5 mm allen but a 3/16 feels close enough to feel the spring pressure for now. Will get a 5mm to make sure.
Interesting the owners manual doesn't even mention this. Like it's a secret or they don't want you monkeying with it ?
I also take it that one should have a chronograph before you do adjust it.
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As mentioned in the other post, they do vome with a threaded rear end cap, degassing screw, and an allen key (at least mine did...and I'd have not found them except I tend to shake the snot out of boxes before I put them away).
So you've a threaded end cap. IF you intend a power adjuster, then the degassing tool would be useless to you (it wouldn't work with a power adjuster in place), so you could (1) make a spring guide and (2) cut the power adjuster short so it just works to compress the spring guide and works as a power adjuster.
Personally, I did my fiddling around/adjusting the "old school" way (cut and try...shim and try again, etc.) with the metal out of the stock (unscoped, just shooting shot counts without sights).
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As mentioned in the other post, they do vome with a threaded rear end cap, degassing screw, and an allen key (at least mine did...and I'd have not found them except I tend to shake the snot out of boxes before I put them away).
So you've a threaded end cap. IF you intend a power adjuster, then the degassing tool would be useless to you (it wouldn't work with a power adjuster in place), so you could (1) make a spring guide and (2) cut the power adjuster short so it just works to compress the spring guide and works as a power adjuster.
Personally, I did my fiddling around/adjusting the "old school" way (cut and try...shim and try again, etc.) with the metal out of the stock (unscoped, just shooting shot counts without sights).
I don't think you understand what I am saying. My spring is seated onto a threaded insert in the end cap that has a hole through it that the degas tool will pass through. The insert where the degas tool can pass through is a 5mm allen wrench. I can turn it in and feel the spring pressure increase against the insert, and the FPS increased when shot over chronograph (though it did use more air and was louder). I am not sure yet as I haven't had a chance at extended testing, but may have to remove a coil (or just end it properly) to go light enough on hammer spring for lighter, flatter tuning.
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Mine doesn't have that (#1217000XX).....there is noting to adjust....which isn't a big issue with me. It's a clear shot from the threaded hole to the rear of the striker.
Figure I'll adjust the spring tension/striker hit until it runs well with a 2K fill (a little under speed with a full 2K fill, climbing up about 4% to a level spot, then declining in speed). Any energy change after than would be a matter of improving air flow to the pellet rather than cranking on the striker spring.