Recent content by Grumpy 49

AR-15/M-16 has a slightly oversized chamber versus the 223 SAAMI standard. A "standard" 223 spec chamber. even using a "MIL" spec 5.56 cartridge, should function without the need for a forward assist. BUT, when the Military added Calcium Carbonate to reduce muzzle flash, between the residual...

Uncle worked at COLT as a Manufacturing Engineer when they started building the M-16 (1960's). Switch to Ball Powder caused the cycle rate to jump from ~600 rpm to almost 1050 rpm. Design was originally "tuned" to the ~600 rpm rate with stick powder. The main issue was the Calcium...