Military seeks lighter, stronger ammo.

• Author: Parsons, Dan
• Position: Inside Science + Technology

There is only so much weight that can be removed from a firearm before it becomes unreliable, unwieldy in the shooter's hands, or vulnerable to damage. That is especially true when it comes to small arms that are used in the extreme conditions of combat.

Recognizing that rifle design using gunpowder and self-contained cartridges has neared the zenith of engineering, firearms manufacturers are turning to ammunition as a possible source of further weight reduction. They are also studying how to make existing bullets more lethal and accurate at all ranges.

"When it comes to the physics and engineering of the weapon itself, we're probably pretty dose to the limit with weight reduction," Greg Ulsh, vice president for military operations at FN Herstal USA, told National Defense. 'At least firearms are much closer to reaching the limit of engineering, the edge of possible physics, than is ammunition. There's still a lot more we can do with ammunition to make the entire system more effective."

The Army wants small-caliber ammunition with lighter cartridge casings than the current brass design that is standard in the industry. That weight reduction should not sacrifice the durability of the brass casing, the Army has stipulated.

Army officials are also looking for ammunition with a reduced muzzle flash and sound signature--both aspects that can alert an enemy to a shooter's position. They want rounds that fire deaner and emit fewer heavy metals and other contaminants.

Soldiers are not happy with the 5.56 NATO round's knockdown power. So Army officials are looking for rounds that "achieve higher incapacitating effects against targets at all ranges" and after "passing through walls, car doors, windshields and other battlefield barriers."

The majority of soldiers carry the M-16 family of weapons that fire the .22-caliber 5.56 NATO round--termed the M855 by the U.S. military. Answers may be found in overall bullet design rather than by tweaking size or caliber, an active Army Special Forces soldier told National Defense.

"The M855 used by DoD is a full metal jacket with a steel core," the Green Beret, who asked not to be named because he was not authorized to speak to the press, wrote in an email. "It simply flies too fast and doesn't fragment enough to have a lot of knock down power."

A bullet--the projectile that is seated into the open tip of a round's casing--is measured in grains, a holdover unit from the Bronze Age when mass was calculated using...