Blank Firing Adapter (BFA), Red, NSN 1005-21-912-8997, for M249-Series Machine Gun

For training exercises, the M249-Series Machine Gun is used with the M249 Blank Firing Adaptor, essentially a steel plug which screws into the muzzle and partially blocks it. (While standard blank firing adaptors for the M16 and M4 family of weapons will fit into the barrel of the M249 SAW, their use has been abandoned in favor of a SAW-specific BFA, due to the risk of catastrophic failure of the weaker rifle BFA, which is not durable enough for sustained automatic fire.) Gas-operated weapons rely on the projectile to trap gas pressure in the system as it leaves the barrel; without this, there will be insufficient pressure to cycle the weapon, thereby necessitating the use of a BFA.  In addition to the requirement to cycle the weapon, BFA's are needed for safety reasons.  It is extremely dangerous to fire blank ammunition using a weapon that does not have a BFA attached to it, due to the risk of burns and injuries from debris leaving the weapon's barrel at high velocity.