MGI, originator of the Bushmaster pistol, has introduced an Enhanced Reliability Firing Pin & Bolt System for use with AR-15 style rifles converted for use with the 7.62 x 39 round. MGI claims that their Firing Pin & Bolt system closely mimics a true AK 47 firing system. Wolf Performance Ammunition agrees and highly recommends using the MGI Firing Pin & Bolt system when firing 7.62×39 ammo in the AR platform.
There have been many attempts ranging from removing metal from the rear of the bolt, or from the flange of the firing pin, in an effort to get more penetration into the harder primers used in many 7.62 type rounds. MGI’s answer was to displace enough mass in the primer to insure detonation. They have combined a harder firing pin with a magnafluxed mil-spec bolt and D-fender D-ring to increase extraction reliability.
www.mgi-military.com