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 close 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 cleaner 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 the average size of cereal grains. There are 7,000 grains in one pound. The U.S. military currently uses a round with a 62-grain bullet in its M-16s. The FN SCAR, used by Special Operations Forces, comes in both the 62-grain 5.56 NATO or a much heavier 7.62 mm. Snipers and crew-served weapons also use the heavier round.
Some forces have access to a 5.56 with 77-grain bullet for the M855 round, the Green Beret said.
“The bullet is great, but isn’t widely available,” he said.
“The 7.62 rounds are obviously better than the 5.56 because they’re bigger. But beyond that, they are lead core versus steel, giving them more knock-down power. If we could get a better bullet in the 5.56 it wouldn’t be an issue, but if we’re going to keep widely using the green tip M855, we’re going to have issues with knock-down power.”
Many of the Army’s desires can be achieved with polymer-cased ammunition, which replaces the brass, steel or aluminum cartridge shell with a plastic composite. Companies like PCP Ammunition claim to be able to reduce the overall weight of ammunition by 30 percent using composite materials.
A laundry list of companies are researching the issue of bullet and ammunition design both for the commercial and military and law enforcement markets.
U.S. troops have had specialty rounds like incendiary and tracer ammunition for decades. On the commercial side, it is almost impossible to count the number of specialty rounds developed for shooting everything from coyotes to zombies. The companies competing for a share of the market include Winchester, Remington and Smith & Wesson, among dozens of others.
FN USA makes eight different rounds specially designed and solely available for military and law enforcement use. They include lead-free for use indoors or where contamination is a concern; a “duty round” with an aluminum core designed to limit overpenetration; subsonic ammunition for use with suppressors that limit the weapon’s sound signature; blank and dummy rounds for training; and tracers that allow for viewing bullet flight path in low light.
Other companies, including some relative newcomers like PCP, have aimed their research specifically at reducing weight by eliminating metal casings.
Savannah, Ga.-based PolyCase Ammunition jumped into the business of manufacturing polymer cartridges only last year, but has since sold more than 1.5 million rounds.
The company’s “ammunition of the future” features single-use casings that prevent reloading but are recyclable. The ammo is designed not only to reduce weight but also to curb carbon dioxide emissions compared with metallic casings. Cutting back on metal components also reduces oxidation, which gives the ammunition a longer shelf life.
The company currently only produces .380 automatic pistol rounds, which are not currently used by the U.S. military. But plans are to expand its production to .45 caliber, 9mm, .40 caliber Smith & Wesson and others, according to information from the company.
No stranger to the use of polymers in firearms manufacturing, FN is also exploring its use in future ammunition designs, Ulsh said. Materials that can withstand both high speeds and high temperatures but are lighter than metal are the Holy Grail at present.
“Where we’re going now, we’re looking to the aircraft and automotive industries for materials that might be useful in firearms and ammunition,” Ulsh said.
The next step in ammunition is the progression away from gunpowder-driven self-contained cartridges to what are broadly termed “smart weapons.” Ulsh said FN has “a few things in research and development right now,” but declined to elaborate.
Plymouth, Minn.-based Alliant Techsystems’ armament systems division is already supplying experimental “smart” ammunition to the Army for its XM25 Counter Defilade Target Engagement System. The 25mm weapon can fire rounds that explode midair at predetermined distances, allowing soldiers to engage enemies hiding behind obstacles or walls. Armor piercing, less-than-lethal and door-breaching rounds for the weapon are under development.Clarification: A special forces soldier who spoke to National Defense for this story was originally identified as an Army Ranger. While he holds that certification, the soldier is an active member of an Army Special Operations group, often called Green Berets.