The M240 is a family of machine guns used by the USA. It was based upon the FN MAG, which is based upon the BAR 1918. It was developed by the US Army in 1977 to replace the M73, M219, and M85. It is a gas operated, belt fed, air cooled automatic weapon. It uses the long piston stroke gas system with the gas regulator, located below the barrel. The bolt is locked using a swinging shoulder that engages the cut in the floor of the receiver. The air-cooled barrel is quick-detachable, with the carrying handle attached to it to help handling the hot barrel. The receiver is made from steel stampings. It is fed using disintegrating steel belts of various lengths. The rate of fire can be controled between low (650 rpm) and high (950 rpm)by different firing techniques, depending on the tactical situation, but the gun can only be fired in full auto. The charging handle is located on the right side of the receiver. The simple folding bipod is attached to the gas block, and there's a mounting point on the bottom of the receiver to fit into the various mountings, including infantry tripods. The open sights are fitted by standard, and some of the latest production versions have Picatinny-style scope mounts on the top of the receiver. Standard guns are fitted with the pistol grip and trigger, and the wooden (early models) or plastic (present manufacture) butt. Coaxial guns (like the M240C) have the trigger replaced by the electric solenoid, and the pintle-mounted versions (like the M240D) have the spade grips instead of the pistol grip and the butt. Loading the weapon is performed by pulling the charging handle which locks the bolt to the rear. The weapon is placed on safe and the charging handle is pushed forward (this is spring loaded on the tank mounted version). The feed tray cover is then lifted and rounds are laid inside the feed tray. The feed tray cover is then closed and the weapon is ready for operation. Clearing the weapon is performed by ensuring the bolt is locked to the rear and the weapon is on safe. The feed tray cover is then lifted, the remaining belt (if any) is swept out of the feed tray, the feed tray is lifted to visually inspect the rear of the barrel and the face of the bolt. Any links or brass casings are removed. The weapon is now clear. In the unlikely event that a live round is on the bolt face, it is knocked loose with a cleaning rod or another rigid object. If there is a live round lodged in the barrel, the operator must immediately decide if the barrel is hot enough that there is a chance of it cooking off. If there is, he will immediately move his face away from the opening of the weapon. He should then wait for the barrel to cool off before attempting to remove it. In many cases, attempting to remove the barrel will cause the round to detonate as soon as the barrel is unlocked from the receiver. He can also attempt to extract the round by taking the weapon off of safe, pulling the trigger and pulling back on the charging handle. This has a fair chance of causing the weapon to fire, so care should be made in ensuring that the weapon is pointed in a safe direction first.
See Also
- BAR 1918
- FN MAG
- M240B
- M240C
- M240D
- M240G
- M240H
- M60
- M249
- Rheinmetall MG3
- CETME Ameli
- FN Mk 48 Mod 0