05-02-2012, 11:33 PM
If it is one of these after-market 7.62x39 copycats using a 5.56 bolt face depth of .124", and you have an actual Grendel, then you can't sahre because of the Grendel's .135" bolt face depth, based on the original Colt bolt face for 7.62x39 made in the late 1980's.
Some have argued that running a bolt through different barrel extensions is a bad idea, since each will have its own shock pattern, which could lead to early fatigue of the bolt. I personally use dedicated bolts for each barrel, and recommend the same.
7.62x39 AR's are a handful if not built correctly, and encounter numerous functioning problems often with parts kist of cheap price points. Even some of the higher-end one require substantial trouble-shooting, namely firing pin mods, magazine mods, feed ramp tweaks, gas system tweaks, and buffer changes.
Some have argued that running a bolt through different barrel extensions is a bad idea, since each will have its own shock pattern, which could lead to early fatigue of the bolt. I personally use dedicated bolts for each barrel, and recommend the same.
7.62x39 AR's are a handful if not built correctly, and encounter numerous functioning problems often with parts kist of cheap price points. Even some of the higher-end one require substantial trouble-shooting, namely firing pin mods, magazine mods, feed ramp tweaks, gas system tweaks, and buffer changes.