The U.S. Air Force is increasing weapons training for its security forces, and all airmen headed for Iraq or Afghanistan. In the past, most training involved M-16 rifle and M-9 9mm pistol. But now there is more training (not just familiarization) on the M-203 grenade launcher, M-240, M-60 and M-249 machine guns, and M-500 shotguns. The air force has also started using the M-4 assault rifle (a shorter version of the M-16), and the more high tech sighting devices, including night sights. The M-4 is particularly popular among air force troops riding with convoys in Iraq, because it is easier to get into action from inside a vehicle.