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AR issue.
- Thread starter BigMike
- Start date
To much oil can cause issue as well. Compare your buffer and your buffer springs to another build. Make sure the buffer tube is the correct length for your setup and that it isnt full of grease.
Clean the weapon, then lightly apply oil to the appropriate moving parts. If all of that fails, bring another known functional ar so you can see if it happens on different lowers or different uppers. (Dont make an sbr though)
I had a barrel the went on a pistol that had the gas port drilled to a small. Theres a chance it can be under-gassed as well. You can tell by the brass extraction patter and/or f you put it on a functional lower and it does the same thing.
Clean the weapon, then lightly apply oil to the appropriate moving parts. If all of that fails, bring another known functional ar so you can see if it happens on different lowers or different uppers. (Dont make an sbr though)
I had a barrel the went on a pistol that had the gas port drilled to a small. Theres a chance it can be under-gassed as well. You can tell by the brass extraction patter and/or f you put it on a functional lower and it does the same thing.
Try some name brand M193 ammo.
If still doing it, try a known good (used) BCG.
If still doing it, put upper on a known good complete lower.
If it is still short stroking, contact PSA customer service and send it in and let them repair it. Once you go pulling the gas block off, etc, you void the warranty on the complete upper you paid for.
If still doing it, try a known good (used) BCG.
If still doing it, put upper on a known good complete lower.
If it is still short stroking, contact PSA customer service and send it in and let them repair it. Once you go pulling the gas block off, etc, you void the warranty on the complete upper you paid for.
The buffer tube, spring, and buffer itself appeared to be identical to all my other carbines, although the buffer is unmarked. I could be completely wrong, but I feel like if its having a gas issue, wouldn't it fail to extract/fail to chamber a round? The gun is cycling perfectly, just catching the carrier instead of the bolt on the last round. If it were only stroking that far every time, it wouldn't pick up the next round. The bolt catch it very tight fitting, not on the lower but on the roll pin. I'm going back to the range today with it with pmags and some full power 5.56 ammo. I'll wipe the bcg down and hit it clp for good measure and report back.
Gas block could be misaligned as well, creating a gas issue. The travel of the bcg doesn’t have to go all the way to lock back position to eject and chamber another round. I’m guessing there is maybe a .25” of travel difference between being able to chamber the next round and being able to lock back.
You could try a lighter buffer, or remove a weight or two from your buffer to see if it locks back then.
You could try a lighter buffer, or remove a weight or two from your buffer to see if it locks back then.
" The gun is cycling perfectly, just catching the carrier instead of the bolt on the last round."
That is called short stroking. Bolt is coming back far enough to pick up next round from mag, but not far enough to properly lock back on an empty chamber.
Could be a gas problem, a bolt drag problem, a gas tube to BCG misalignment, an out of spec lower receiver (only one I ever saw was an Anderson lower), an out of spec mag, etc. Lots of possibilities, but sounds like you are investigating one at a time.
That is called short stroking. Bolt is coming back far enough to pick up next round from mag, but not far enough to properly lock back on an empty chamber.
Could be a gas problem, a bolt drag problem, a gas tube to BCG misalignment, an out of spec lower receiver (only one I ever saw was an Anderson lower), an out of spec mag, etc. Lots of possibilities, but sounds like you are investigating one at a time.
Did I read correctly that the malfunction only happens on the last round in the magazine?
I wouldn't even think about a gas problem until I tried a different magazine.
I wouldn't even think about a gas problem until I tried a different magazine.
There is a roll pin that you drive out. Do you know what weight buffer you have in there now?
