Barrel Length Studies in 5.56mm NATO Weapons

I suspect that part of the issue revolves around the massive cost of bringing a new weapon system on-line with its separate ammunition and spare parts requirements. The US has expended massive amounts of money over the last 60 years in R&D to produce the various "PIP" versions of the original M-16 (e.g. M-4, etc.). As a cost saving measure, if they can use something already in the logistics pipeline, they will. The US Govt. isn't worried about the rifles wearing out more quickly if they can save millions on R&D. There is also the tendency to look for one solution to every problem.

For civilian users the issue is exactly the opposite. Semi-automatic handguns are available for civilian purchase. Who in their right mind would want a larger semi-automatic "pistol" for practical applications? On the other hand a smaller "rifle" with a rifle cartridge can be very appealing (if not deafening). I can only recall a handful of situations where I used a rifle on full and a couple of those times I just became confused in the stress and panic associated with an unexpected enemy encounter at super close range. A semi-auto rifle is an optimal firing platform. A semi-auto sub-gun in a pistol cartridge isn't nearly so much.

While a 9mm or .45 cal selective fire weapon may be less than optimal solution; to attain a shortened weapons length without extreme muzzle blast and report. In a confined urban environment as found in older European and Middleastern cities, it may be a more practical tool. Prior to the issuance of the M16A2, those of us trained with the M16A1 had to develop and practice trigger control to keep from spraying and praying. Usually those soldiers were designated as squad automatic riflemen. Going into historical studies of Combat, massed suppressive fires were often used along with aimed fires to isolate and eliminate targets. When you compare the overall length of some post WWII submachine guns, you find that they too were attempting to balance ballistics, accuracy, and functionality. The US Armed Forces are already employing several calibers of weapons with differing supply lines; 7.62mm; 5.56mm; 9mm; and limited .45cal. Additionally the Army is to soon to introduce a 6.8mm round. While a .274/6.8mm family of calibers offer enhanced ballistic performance over 5.56/.223 family of weapons, it will also create a further issue of weapons and ammunition supply overlap untill required stocks are available for the Active, Reserve, and Guard. Then not to consider the requirements of our sister branches in regards to their weapons needs and use. Then we should consider the needs of vehicle crews and operators in regards to a weapons length and storage. There is more to consider as well, but until a shorter weapon can be developed that controls flash, and report, you will have a problem with soldier acceptance, and balancing the needs of the force and the desires of the bean counters. I am only suggesting that a selective fire submachine gun can bridge the gap between side arms and carbine length rifles where a shorter weapon may be desirable by troops. As we transition to an era where urban warfare becomes more likely, we should review and evaluate the urban combat lessons of WWII where US Forces discovered breaching walls between structures and moving internally was safer than exposure on the streets as well, and how weapons were employed in those operations.