November 2, 2007: The U.S. Army is replacing the M203 40mm grenade launcher with the M320 next year. The M203 fits under the barrel of the M16 rifle (and similar weapons) , and has been in use for forty years. The army is buying 71,000 M320s (for about $3,500 each) to replace the 50,000 M203s it still has. The M320 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 M16 with the addition of a stock.

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. In over a year of testing, the M320s sighting system was seen to make the weapon 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.