Since that, I have fire more than 30 rounds without any failure...
I don't know why the Recoil Buffer cause that!?!? Maybe it's a mix of two problems.
I think I will shim the gaz lock. When I have tighten it, I was able to turn it one quarter further. Maybe I still loosing pressure from there...
The Recoil Buffer is not a good idea on the M14 !!!!!
you do not need it .
No need to mod the mount ,the best thing to do is a new shorter punger/spring,extractor .Or the one you have can be shortend 2 coils i think .I have never done it myself so seek trimming info from the doc or someone on the board who knows for shure !!
To do so requires disassembling the bolt group, which is a MAJOR pain to reassemble afterward, unless you have a "bolt assembly tool". I watched as this modification was done several times at the last Clinic, the removal and shortening/trimming of the extractor spring. Your best bet, other than buying the tool for $50, is to attend a clinic.
It's seem a complex operation. Before doing it I will test further my M14 to see if the Scope Mount cause any problems... lol