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Posted: 7/1/2013 11:35:38 AM EDT
Rifle length upper, this is on a carbine lower, worked fine for few thousand rounds, Bolt catch not catching bolt but carrier, usually wont stay open on last round, sometimes wont pick up next round. This has to be a classic symptom of something, help appreciated |
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Is your hammer a cut face and is the bottom of your carrier cut like an SP1? It looks like the timing of the carrier in your pic is correct for the hammer being hung up on the carrier firing pin due to a sear issue, but I dunno. [goes to get A2 colt with SP1 FCG] Nope.
Sly |
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Pull the buffer and recoil spring, and check the cavity of the tube for debris (blown primer or something that is not allowing the buffer to come all the way back to the end of the buffer tube).
Also to point out, if you are using a telescoping type butt stock, then you should be using the shorter carbine buffer and shorter 10.5" recoils spring as well, hence not a standard longer buffer and standard longer 11.75" recoils spring. |
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With the solid tags of the brass to the defector, I still think that it's either the spring that it too long, or the tube too short.
Lock the bolt back on the catch by hand with the charging handle, and during the last inch of pull back on the charging handle, the tension on the handle should not increase. If it increases, then either the spring is coil binding up, or the hammer is wedging tail is wedging between the bottom of the carrier to the top of the trigger. Also, have you tried to move the catch by hand in the receiver to confirm that its not the catch that is binding in the receiver slot and the problem at hand instead? |
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Quoted:
That upper is running fine on a different lower with the VLTOR A5 system, so that combo just didnt jive You can mimmick the A5 with an H2 buffer and a USGI spring if you want. This combo most closely matches the physics of the a5. This is the Canadian formula on their C7 whatever military rifles. |
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