I had a well known gunsmith build a custom 7.62x39 AR barrel for me using a 12" AK47 barrel (b/c it is hammer forged AND chrome lined). Had a couple of problems of which I fixed one. The other one is an over gassed system, I think. Here is the scenario:
Insert mag, chamber a round, round fires, it usually extracts/ejects fine, action chambers a new round, fires but won't extract AND the bolt is stuck forward. I have to take a cleaning rod and tap it loose. Sometimes this happens even after the first round. Also, sometimes the case rim would be ripped off or the case rim would be badly damaged. I have tried a LW bolt, a COLT bolt and a CMT bolt with exactly the same problem. I doused the carrier, bolt and extension with lube with exactly the same results. I put in the heaviest buffer I could find with the same results (MGI RRB and a 9mm buffer). I finally took off the FSB and used a pin gauge on the gas port. It measured .091 and I am guessing it should be somewhere around .074.
What do the experts think?
If the consensus is over gassed, then I will try an Wolf Extra Power recoil spring since I have one sitting in my parts bin.


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