After three years of development and testing, the U.S. has begun issuing a new 40mm grenade launcher to troops. The 82nd Airborne Division began receiving M320 grenade launchers last month, replacing the elderly M203s.
What the U.S. actually did was adopt a version of the German designed AG36 40mm grenade launcher, as the M320. The British did the same, calling their version the L17A1. All these grenade launchers fit under the barrel of an assault rifle (and similar weapons). The first of these weapons was the 1960s era U.S. M203. The AG36 is similar to the M203, but is easier to use, has its own pistol grip, is more accurate and can be used separately from an assault rifle with the addition of a stock. This is popular, because troops in Iraq and Afghanistan have complained about no longer having a shotgun like 40mm grenade launcher (the Vietnam era "thump gun"), that allowed for more rapid and accurate fire by an experienced grenadier. The new launcher can also be reloaded while the user is prone, because it slides to the side, rather than down, for reloading.
The biggest improvement with the M320 is its sighting system, which features a laser range finder. At night, an infrared range finder enables a soldier wearing night vision goggles to see the light beam. The M203 was not designed for night use. The M320s sighting system has proved to be much more accurate than the older M203. This was particularly the case with new users. With the M203, you got better after you had fired a hundred or so rounds. That took time, and was expensive (the 40mm grenades cost about $28 each). The 40mm grenades weigh 19 ounces each and have a range of about 400 meters. The grenade explosion can kill within five meters, and wound up to ten meters or more.
Users of the AG36 and M320 are also getting longer range 40mm grenades, giving the weapon an effective range of 800 meters. This is possible because the M320 breech swings open to allow for longer (up to nine inches) grenades. The U.S. SOCOM (Special Operations Command) uses a variant of the AG36. All these AG36 variants weigh about 3.3 pounds. The U.S. Army is buying 71,600 of them, for about $3,500 each.