Weapons: The XM8 Lives, Sort Of


p> March 14, 2007: Back in 2005, the U.S. Armys design for a new assault rifle, the XM8, was cancelled. But now the manufacturer has incorporated one of the key components of the XM8 into M4 rifles, and calls the hybrid the H&K 416. Heckler & Koch (H&K) designed the XM8, which was based on an earlier H&K rifle, the G36. SOCOM is using the 416, but no one else is (except for a few police departments).


The XM8 had one major advantage over the M16. The XM8 (like the G36 and 416) uses a short-stroke piston system. The M16s uses gas-tube system, which results in carbon being blown back into the chamber. That leads to carbon build up, which results in jams (rounds getting stuck in the chamber, and the weapon unable to fire.). The short-stroke system also does not expose parts of the rifle to extremely hot gases (which wears out components more quickly). As a result, rifles using the short-stroke system, rather than the gas-tube, are more reliable, easier to maintain and last longer.

H&K developed the 416, for SOCOM, at the same time the XM8 was being evaluated by the army. SOCOM got the first 416s in 2004, a year before the army cancelled the XM8. The 416 looks like the M4, for the only thing that has changed is the gas system that automatically extracts the cartridge after the bullet has been fired, and loads the next round.

In dusty places like Iraq and Afghanistan, you have to clean your M16 and M4 rifles constantly, otherwise the combination of carbon and dust in the chamber will cause jams. The army and marines both decided to stick with their current weapons, rather than adopt an easier to maintain weapon, like the XM8 or 416, because of the billion or so dollars it would cost to switch rifles.  If the issue were put to a vote, the troops would vote for a rifle using a short-stroke system. But the military is not a democracy, so the troops spend a lot of time cleaning their weapons, and hoping for the best.