10-04-2011, 12:23 AM
Written by Bureau of Alcohol, Tobacco, Firearms and Explosives (BATFE), Chief of the Firearms Technology Branch
...M16 bolt carriers are not designed and inteded solely and exclusively for use in converting a weapon into a machinegun and are not any combination of parts from which a machinegun can be assembled. Further, an M16 bolt carrier is not a firearm as defined in the GCA or a machinegun as defined in the NFA. An M16 bolt carrier is simply a machinegun part and as such its domestic sale and possession is unregulated under the Federal firearms laws. It is not unlawful to utilize a M16 machinegun bolt carrier in a semiautomatic AR15 type rifle.
Anyone who still believes M16 BCG's are no-no needs to realize that they are safer to use in an AR15, and there is nothing regulated with them. Light carriers can lead to case head separation with hotter loads or longer bullets, if the buffer, recoil spring, and adjustable gas block are not used to increase the lock time. Lightweight carriers definitely reduce lock time, which is not good, especially in carbines with 16" barrels and carbine-length gas systems (a gas system length that was originally designed for 10" barrels).
...M16 bolt carriers are not designed and inteded solely and exclusively for use in converting a weapon into a machinegun and are not any combination of parts from which a machinegun can be assembled. Further, an M16 bolt carrier is not a firearm as defined in the GCA or a machinegun as defined in the NFA. An M16 bolt carrier is simply a machinegun part and as such its domestic sale and possession is unregulated under the Federal firearms laws. It is not unlawful to utilize a M16 machinegun bolt carrier in a semiautomatic AR15 type rifle.
Anyone who still believes M16 BCG's are no-no needs to realize that they are safer to use in an AR15, and there is nothing regulated with them. Light carriers can lead to case head separation with hotter loads or longer bullets, if the buffer, recoil spring, and adjustable gas block are not used to increase the lock time. Lightweight carriers definitely reduce lock time, which is not good, especially in carbines with 16" barrels and carbine-length gas systems (a gas system length that was originally designed for 10" barrels).