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Posted: 9/14/2012 3:59:19 AM EDT
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Hey all:
I took my new build out to the range yesterday and encountered a bunch of problems. I'm using a CMMG 22lr upper. Trigger is a Geissele National Match. Was shooting Federal Automatch which is rated around 1200 fps, figured it should be hot enough to cycle the gun. First few rounds went fine. Then I had a failure for the hammer to reset, pulled back the bolt; live round with no firing pin mark in the chamber. Dropped the mag, closed the bolt and round proceeded to fire. This continued for a while, about 3 rounds no problem, then a failure to reset the hammer. Then something bad happened, I was shooting and my third round resulted in a loud bang and much smoke coming out of the gun. Pulled back the bolt; rim had separated from the case!!! So I ended up with a stuck case with no rim in the chamber. At that point I packed up and went home. 1. Is the problem regarding the hammer not resetting because I'm not using hot enough ammo? 2. How the heck could I have a rim blow off on me? I'm assuming that somehow the gun fired without the bolt being fully closed? I have used Federal Automatch extensively with my Ruger MKIII and never had any problems with it. Thoughts would be appreciated. |
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This would be my thought too or possibly the bolt is dragging somewhere. Operate it manually to check the latter.
I'm going to start a thread in the CMMG Industry Section about this very subject. It can happen with any of the semi auto 22's made and I want to get the info established that will minimize the possibilities.... Dave |
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I've run a Timney 4 lb - no problem. Accuracy Speaks - no problem (except when I put in the light, yellow springs). RRA 2-stage - no problem. Geissele SSA (current trigger) - only problem was I had to file down the contact point at the back of the bolt on my Spike's bolt. The Cieners are fine. Spike's actually hung up slightly when drawn back.
My latest Spike's midlength build is happily chewing through my stash of CMP Aguila SV ammo - which has never run well in any of my other dedicated uppers. As SpecOps-13 advised above: Check to see bolt is not dragging - mag lips, hammer and bolt catch. Some bolt catches can cause problems as they are a skoosh bit higher than others. Hate to say this but a few early lots of Fed Auto Match was so bad that some shooters said Federal was quietly exchanging them. I had a couple boxes - misfires and rounds that by sound, function and recoil were loaded to different power levels. Gave a half box to my friend who later told me the ammo shot horribly in his Marlin bolt and a bunch would not fire at all. I could not exchange my ammo cause no practical way of shipping small quantities of loaded ammo to and from Hawaii.  I've shot other Federal .22 ammo without problem so I know it was just the one or two lots of bad ammo.
YMMV |
| Just curious if your new build had stainless steel bolt or parkerized? On new parkerized bolt it helps to run the bolt on the wet side till worn in. Some lubes are better than others but your usually wise to use some type of lubricant. With a dry new upper a round can easily fail to completely chamber resulting in an Out Of Battery. Main thing is no one gets hurt and check the bore for a lodged bullet. If there is a bullet lodged in the barrel they are easley removed with a cleaning rod. |
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Quoted:
I have never had any luck with Fed Auto Match in my Atchison type conversions. Dave N Thanks Dave - maybe my experience with the Auto Match wasn't just a bad batch. Federal 810 (when I can find it) always runs in my uppers. CCI SV and Mini Mag is still my go-to for any new upper - most consistent .22 ammo I've found for function (and the accuracy is generally decent too). YMMV |
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I have learned from experience to always check for a broken firing pin first.
Edited for more info: I was recently having problems with the kit loading the first round from the magazine. Long story short, the firing pin had broken(again) and the skinnier front part was stuck in the fired position. If I pulled back on the bolt slightly to where the round could get in front of the firing pin then it would chamber normally. I didn't know it was broken at this time. There were a few jams which was unusual for a kit that normally runs close to 100%. I figured it was just dirty and when I cleaned it the first thing I noticed was the firing pin sticking out the bolt face. It is surprising how well they work with a broken firing pin and this can lead you to think it is something else. |
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Tried minimags and also Federal Gameshok (another 'hotter' round). The Federals worked the best, the CCI's had the same problems as the Federal Automatch, failure for the hammer to reset in the cocked position. The Federals would reset the hammer about 30% of the time.
Threw in a TACCOM reliability kit last night (different firing pin with shims, and buffer tube plug) and also put in a JP lighter hammer spring. Took it out this afternoon with CCI Minimags; no difference at all, same problem. Ordered a CMMG trigger; I guess that's the only thing left to try. |
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Quoted:
Tried minimags and also Federal Gameshok (another 'hotter' round). The Federals worked the best, the CCI's had the same problems as the Federal Automatch, failure for the hammer to reset in the cocked position. The Federals would reset the hammer about 30% of the time. Threw in a TACCOM reliability kit last night (different firing pin with shims, and buffer tube plug) and also put in a JP lighter hammer spring. Took it out this afternoon with CCI Minimags; no difference at all, same problem. Ordered a CMMG trigger; I guess that's the only thing left to try. Have you tried a standard trigger just to test for function? +1 on the Fed Gameshok - that's the 810 I mentioned above. Only trouble is it's expensive and often "Not in Stock". Only ammo that runs consistently in my CZ22 upper and a friend's .22LR Garand and M1A (he builds these out of actual M1s and M1As - they are works of art - last round hold open and everything). |
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failure to reset.....
I will submit that your problem is dwel time, not failure to fully cycle. The bolt is moving so fast that there is not enought time for the disconnect to catch. You mentioned that the Auto match worked 30% of the time.....all others were worse. Try some subsonic ammo....or even match ammo that is around 1080fps Tim |
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quote]Quoted:
failure to reset..... I will submit that your problem is dwel time, not failure to fully cycle. The bolt is moving so fast that there is not enought time for the disconnect to catch. You mentioned that the Auto match worked 30% of the time.....all others were worse. Try some subsonic ammo....or even match ammo that is around 1080fps Tim[/quote] Tim - you have a valid point that I had not thought of. I once emailed Mr. Kuehl who built my first dedicated upper - that my upper functioned best with a full length or nearly full length Lakeside recoil spring. He said it was probably because it was holding the bolt closed just a skoosh longer and slowing down the cycling of the bolt. One of the most reliable rounds in all my dedicated uppers is CCI Standard which is rated at around 1070 fps. I run an Accuracy Speaks trigger in one of the lowers I use a lot for .22 dedicated uppers. With regular springs it works fine - with yellow LW springs it was nightmare. Failures to reset, hammer not cocked. The worst was the rifle would sometimes fire when the trigger was released. IIRC - I remember release triggers on some competition shotguns but never on rifles. Very nerve wracking. 
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Yes, I have cleaned and lubed the bolt assembly and have worked it back and forth both manually and via the charging handle and it doesn't seem to have any hang-ups.
The only thing I can think is that the Geissele hammer is too short to get pushed down far enough by the bolt to be captured by the disconnector. I ordered a CMMG trigger, which honestly I really don't want to run as the Geissele is a serious match trigger and comes with the associated 'match' price-tag. The Geissele is a really nice trigger; I'm going to be very disappointed if I can't run it. I guess it should work with any .223 upper, but it kind of defeats the purpose of having a 22lr upper to practice with if I have to use a different trigger to run it. The idea that the bolt is moving too fast is interesting. I haven't seen any like 'extra strength' recoil springs for .22 conversions; do they exist? Honestly, I'd prefer to shoot standard velocity ammo anyway if I can as I don't mind paying for a little more accuracy. I've got lots of CCI SV and other SV rounds I can test, along with a number of subsonic loads. Anyway, if you guys have any other ideas, I'm open to hearing them. |
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Quoted:
Yes, I have cleaned and lubed the bolt assembly and have worked it back and forth both manually and via the charging handle and it doesn't seem to have any hang-ups. The only thing I can think is that the Geissele hammer is too short to get pushed down far enough by the bolt to be captured by the disconnector. I ordered a CMMG trigger, which honestly I really don't want to run as the Geissele is a serious match trigger and comes with the associated 'match' price-tag. The Geissele is a really nice trigger; I'm going to be very disappointed if I can't run it. I guess it should work with any .223 upper, but it kind of defeats the purpose of having a 22lr upper to practice with if I have to use a different trigger to run it. The idea that the bolt is moving too fast is interesting. I haven't seen any like 'extra strength' recoil springs for .22 conversions; do they exist? Honestly, I'd prefer to shoot standard velocity ammo anyway if I can as I don't mind paying for a little more accuracy. I've got lots of CCI SV and other SV rounds I can test, along with a number of subsonic loads. Anyway, if you guys have any other ideas, I'm open to hearing them. Lakeside Machine springs are good - http://www.lakesideguns.com/title1/spring.html http://blackdogmachinellc.net/ciener-lakeside-spring-kit.aspx |
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Quoted:
FWIW, I run a Geisselle SSA in my Bushmaster and CMMG conversion kit with no issues. Something to consider if you don't like the CMMG trigger group. I've run the same trigger in my 5.56 and .22 dedicated - in the Spike's build - it produced almost flawless functioning right from the beginning. I pulled it recently to go back to the Timney because I'm doing some accuracy testing. The SSA feels the heaviest in terms of the hammer spring but .22 upper just ran and ran with it. At the conclusion of our collector club's annual silhouette match I loaded up around 180+ rounds during our mad minute (two teams each knocking down 40 silhouettes as fast as possible) I fired and fired and guys were laughing as I shot. They later said all they heard was a near continuous "pok, pok, pok" and shells ejecting and iron chickens and rams and pigs and turkeys with bullets hitting all around them. Not one stoppage. Our team won but not because of me. I must have fired a bunch of shots for every "animal" I took down. 
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Out of many hundreds of 22 kits of several brands I have never had a 22 bolt travel too fast for a good trigger group to reset and I have
used weaker recoil springs and even cut them down to make them weak enough to cycle the weakest and the strongest ammo. Check your trigger group for a bad spring, broken pin or maybe not installed correct. Try your upper on another lower as I have had lowers that were out of spec bad enough that they held the trigger group lower and the 22 kit bolt would not rest some brands of triggers groups. Remove the 22 kit, clean the chamber and check it for a nasty scratch, burr or any other defect as if the chamber is messed up it may be holding the round from chambering all the way and holding the spent brass tight enough to slow down the cycle. Does the ammo that you are shooting drop in the chamber when clean or do you need to push the round in with you finger and it feels very snug ? I have seen a firing pin strike on the edge of the chamber entrance cause extraction of the spent brass to slow down, the dent was small enough to allow the fresh round to chamber but when fired the brass would swell up just enough so the dent would hold the brass and slow down the cycle. |
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Well I finally got my CMMG trigger and installed that and the CMMG hammer using KNS pins. My lower is a Spikes so I doubt its out of spec. I also installed a heavier recoil spring.
The thing is finally working. Now granted, the CMMG trigger is absolutely crap compared with the Geissele National Match trigger, which really disappoints me, since the Geissele was not cheap. I shot about 200 rounds last night, 3 malfunctions; two failures to feed where the bolt came forward and deformed the cartridge and one failure to eject. I also shot 10 rounds of CCI SV just to see if it would cycle; it did just fine. The CMMG trigger has a nasty 'click' when it is released to reset. The Geissele is so much smoother, no creep, very smooth. I guess my next order of business is to see if there's any way to adjust the Geissele so I can get it to work. |
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