Cannonball888
Member
Hello,
Can anyone tell me if a 1970's Colt SP1 receiver is compatible with a USGI M16 A1 Colt upper. I am also interested in knowing what size takedown or pivot pins preban Colt uppers and lowers took vs post ban Colts?
Can anyone tell me if a 1970's Colt SP1 receiver is compatible with a USGI M16 A1 Colt upper. I am also interested in knowing what size takedown or pivot pins preban Colt uppers and lowers took vs post ban Colts?