Franklin Armory Ar-15 BCG "Bolt Carrier Group" come in the following calibers:
*5.56 NATO
BCG
SPECIFICATIONS:
*Carrier machined from 8620 Steel
*Bolt machined from Carpenter No. 158 steel
*MPI Bolt
*M16 full auto style
*Properly staked gas key
*Polished finish
*Franklin Armory logo included