Surface treatment per qq-p-416, type 1, class 3 for top plate only; manganese phosphate, type m, or zinc phosphate, type z, per mil-p-16232, class 1, except for top plate; top plate=aisi 01, hardness rc26-32; bolt carrier=8620, cold drawn stress relieved steel, brinel hardness 217-229; bolt= carpentersteel 158, brinel hardness 195-235; ejector pin=titanium; locating pin=aisi 01, hardness rc26-32
An item consisting of a bolt carrier, a breech bolt, a top plate, and a locating pin. It replaces a breech bolt in a rifle or machine gun to alter the operation of the weapon from gas to blow-back so that low-powered practice ammunition may be used. It is not intended for non-practice usage. Excludes bolt, breech and breechblock.
Classification: Parts and accessories for military rifles of heading 9301
NSN 6110-00-363-3974
NSN 6105-01-466-9090
NSN 5975-01-462-2595
NSN 6110-01-361-0065
NSN 6135-00-351-8606
NSN 5985-01-625-2159
NSN 5998-00-738-1830
NSN 5935-01-116-2132
NSN 6110-00-774-1792
NSN 5975-00-114-0019
NSN 5965-01-221-0569
NSN 5990-00-665-4105