AR 15 Armorer’s Course

[LRRPF52]

I listed SOTAR’s armorer tool list he uses for 5.56 AR-15s, some of which I have, and others I don’t.

Bill Alexander’s approach for the 6.5 Grendel in the AR-15 is starting from a TDP-compliant set of parts, with his design for the bolt, barrel, and magazines being the different parts with their own gauges and standardization.

I just watched a SOTAR video on an AR-15 a friend sent him to fix, where he found many critical parts totally out of spec that he ended up replacing and correctly installing.

Gas port was way too large, barrel was sloppy in the upper, carrier key wasn’t installed right, extractor spring was worn and compressed, recoil spring was past its life with visible compression well below the spec, roll pins were all spiral pins installed too tightly, gas block was loose-fit, castle nut was thread-locked on out of correct position, barrel extension was really sharp and jagged-edged.

That was on a Black Rain Ordnance carbine.