A shorter and lighter version of the M16A2, the M4 carbine is in active use with US forces around the world, and in particular in Iraq, which is why it's mentioned here. Being shorter and lighter than the M16, it is especially useful in close quarter combat and cramped conditions. All is not rosy in the M4 world, since it is frequently criticized for not being as good a weapon as it could be. Senator Tom Colburn sent a letter to the Army in the spring of 2007 urging reconsideration of this gun, an excerpt follows:
I understand that the Army decided to procure M4 Carbines in the early 1990’s to fill the gap between the M16 and 9mm pistol. At that time the Army specifically framed the requirement as the “Required Operational Capability (ROC) for the M4 Carbine.” M4 is a trademark name owned by Colt. Is it standard practice in Army acquisition to tie a requirement to a trademarked product?
I am certain that we can all agree that America’s soldiers should have the best technology in their hands. There is nothing more important to a soldier than their rifle, and there is simply no excuse for not providing our soldiers the best weapon – not just a weapon that is “good enough.” Unfortunately, considering the long standing reliability and lethality problems with the M-16 design, of which the M4 is based, I am afraid that our troops in combat might not have the best weapon.
Is it worth noting that no expense seems to be spared for fancy aircraft (B-2, F-22) or ships (pick a supercarrier), but that the Army and Marine Corps get shafted on weapons quality and "minor things" like armored Humvees and body armor?