These are my M16 full auto BCG that shows properly staked gas keys, the one on the left is a Colt the rest are older LMT (non MIM gas keys).
Quoted:
This will be my 1st build and I am a newb. However I've spent hrs reading here, learning a lot!
What is the difference in operation between the M16 and the AR15 BCG's? If I'm building an AR 15, will the M16 BCG work like a regular AR-15 with all AR parts?
BTW, I live in Cal., is this a problem buying the M16 BCG?
+1 It is not unlawful to utilize a M16 machinegun bolt carrier in a semiautomatic AR15 type rifle (unless you have a state or local law that specifically states it).
Major gun manufacturers that sells California compliant AR the good ones sells with M16 BCG (for example Colt and others).
Desirable features to look for are mil-spec manufacturing process such as shot peened bolt, high pressure tested (HPT) and magnetic particle inspected (MPI) bolt, chrome lined gas key and carrier, and properly staked gas key.
Some of the recommended brands that have these noted desirable features:
Colt
BCM
Daniel Defense
Rainier Arms ThunderBolt
AR Performance (9310 steel alloy) SuperBolt
Spike's Tactical