The Right Round
Written by Peter Buxbaum
SOTECH 2010 Volume: 8 Issue: 4 (June)
With Stopping Ability Key, Finding the
Right Round for the Mission is Critical.
The use by British Army foot patrols in Afghanistan of weapons using 5.56 caliber ammunition has revealed some of the limitations of that variety of bullet. The soldiers complained they were being outranged by, and therefore unable to return fire to, Taliban fighters armed with Russian-made AK47s using 7.62 caliber ammunition. As a result, 7.62 weapons were once again issued to the British patrols.
The United States military uses a number of different calibers of small arms ammunition, including both the 7.62 and 5.56 caliber rounds. The 5.56 mm M4 carbine is the standard rifle now issued to U.S. Army troops. The advantages and problems associated with both varieties of ammunition are of concern to U.S. military officials as well.
Comparing the 7.62 and 5.56 caliber ammunition in isolation reveals trade-offs between the two. The 5.56 ammunition and weapons are lighter in weight, easing the burden on dismounted warfighters. They have less stopping power, and are also less likely to penetrate doors and walls, but the latter attribute can be an advantage in urban combat situations where the prevention of collateral damage is important. But they also have a much shorter range than the 7.62—its energy and lethality rapidly fall away after about 300 meters—making them less effective in standoff engagements with an adversary.
The 7.62 mm round can easier drop an enemy and has a much longer range than the 5.56, but both the ammunition and the weapons that fire them are weightier. The 7.62 weapons also have significantly greater recoil, making them harder to control in automatic mode. The recoil also makes it more difficult to train recruits to shoot accurately.
A key question for decision-makers concerning the next generation of weapons is whether these two different calibers of ammunition should be replaced both with one general-purpose round, which would equip all troops with weapons effective at multiple combat ranges. The United States Marine Corps manages dozens of small arms ammunitions used by the Corps. The Marine Corps Systems Command, Program Manager for Ammunitions (PM AMMO) is responsible for research, development, acquisition activities and total life cycle management support.
“PM AMMO is actively managing more than 60 small arms cartridges used by Marines,” said a Marine Corps Systems Command spokesperson. “This small arms family of ammunition includes various cartridges from 12 gauge to 9 mm to 5.56 mm and up to the .50 caliber. The major factors utilized in the selection of any item in support of the Marines, is determined by the specification provided by the users.”
The deputy commandment, Marine Corps Combat Development and Integration (DC CD&I) examines the need for a particular item and then solicits the specific requirement necessary to allow the users to complete their mission. These specifications include accuracy, lethality, effectiveness against barriers, interface with the weapon, cost and industrial base capacity.
On the requirements side, Marine Corps CD&I produces the total munitions requirement (TMR) in conjunction with the program objective memorandum. “The TMR is a living document,” said the Marine Corps spokesperson. As new requirements are identified they are then validated by the deputy commandant for plans, policies and operations (DC PP&O), DC CD&I’s Fire Maneuver Integration Division and the Marine Corps Training and Education Commands’ (TECOM) Ground Training Branch.
The Marine Corps has an effort under way to modify of the 5.56 mm round, according to the Marine Corps spokesperson. “Based on testing, it was determined that the existing M855 [5.56 mm] round does not meet Marine Corps performance requirements in an operational environment,” said the spokesperson. “This new requirement did not originate from an urgent need from theater, but as a result of a Marine Corps combat assessment on the ammunition during the early part of Operation Iraqi Freedom.”
The result of Marine Corps efforts was the development of the SOST (Special Operations Science and Technology) round, also known as the 5.56 mm MK318 Mod O. The SOST round “was developed for four reasons,” said the Marine Corps spokesperson. “Improved longrange accuracy, blind-to-barriers performance, consistent terminal ballistics, and reduced muzzle flash.”
The SOST round was introduced to the Afghanistan theater relatively recently. As a result, and coupled with the high tempo of operations in that area of operations, “We have no performance results at this time,” said the spokesperson. “We have been in contact with the Marine forces currently engaged in the fight. The intent is to gain substantive performance feedback from those units issued this round. At this time, it would be premature to offer any preliminary assessment.”
The 7.62 round has also come in for some criticism, according to Thomas Mauritzson, vice president for business management at Nammo Small Caliber Division, which manufactures both 7.62 and 5.56 caliber ammunition. “There have been discussions concerning the 7.62 round that it doesn’t give enough bang for its weight,” he said. “There is concern about the weight warfighters are carrying with the ammunition together with the weapon.”
Lightening the load of special operations and other ground forces is a key goal of infantry weapons development. Soldiers’ gear these days, including rucksack, weapon, ammunition, helmet and other equipment can weigh over 130 pounds.
“There is always a difficult balance,” said Mauritzson. “If you want long range performance you need the bigger caliber 7.62 round.”
With regard to 5.56 round, “there are many misunderstandings,” said Mauritzson. “The 5.56 performance is intended to have good penetration equal to the 7.62 and over relatively long ranges [up to 500 meters]. You need to hit the enemy in the appropriate area to get the right effect. The European approach is that training is the key to success.”
Gabe Bailey, marketing director for combat rifles at FNH USA, believes there is a requirement for both calibers of ammunition. FNH is a Belgian company that won the contract to manufacture the Special Operations Forces Combat Assault Rifle (SCAR). The four weapons within the SCAR program include those which fire 5.56 mm and 7.62 mm ammunition.
“They both can be used for the same mission to a certain extent,” said Bailey. “The 7.62 is designed for longer ranges and has more impact on a target than the 5.56 caliber.”
Based on tests performed by FNH, Bailey concluded that the maximum range for the 5.56 round is 500 meters. “At 500 meters it stops doing what it needs to be doing,” he said. “But it also depends on the length of the barrel. The longer the barrel the farther you can shoot. For example, with a 14 inch barrel, you are pushing at 400 to 500 meters.”
On the other hand the range for the 7.62 reaches to 900 to 1,000 meters, according to Bailey. “If you are looking at an urban combat environment, you are talking about ranges of zero to 200 meters,” he said. “In mountainous terrains like you have in Afghanistan, 300 plus yard ranges are what you are looking at.”
In Afghanistan, at least 50 percent of combat engagements take place at ranges of between 300 and 900 meters, according to published reports.
“There are a couple of reasons for the military to be carrying both,” said Bailey. “The 5.56 round is not going to punch through cinderblock. In an urban environment, this is suitable for minimizing collateral damage. You don’t want to shoot through a wall and into the next house.”
On the other hand, because the 7.62 ammunition and weapon are heavier and produce greater recoil, they might not be suitable for every warfighter. “Maybe not every warfighter can carry those,” said Bailey. “Because of that and the higher recoil, it makes sense to have two calibers.”
Another way to think of the 7.62 versus 5.56 conundrum is that the 7.62 is a battle rifle, sniper and support weapon round, best used for suppressing fire or for long range engagements. The 5.56 is an assault rifle round best used for short to medium range engagements.
Some efforts have been under way to retain the lethality of the 7.62 round, but in a version compact enough to be used in lighter modified 5.56 mm guns. One of these is the 6.8 mm Remington special purpose cartridge, developed with U.S. special forces to deliver better effectiveness at 300 meters while being fired from short-barreled carbines. Another suggestion has been the 6.5 mm Grendel round, which sports a slimmer but longer bullet and reportedly provides excellent aerodynamics, enabling the cartridge to match the energy delivered by the 7.62 mm round at 1,000 meters. The weight and recoil of both the 6.8 mm and the 6.5 cartridges fall roughly midway between 5.56 mm and 7.62 mm.
“We really don’t see any justification for the 6.8 mm round,” said Nammo’s Mauritzson. “When you analyze the performance of the 5.56, you find that most errors as a result of distance and judgment errors. Human errors come about when shooters are under stress. It doesn’t matter if he’s shooting a 7.62, 6.8, or 5.56 if the shooter can’t hit a target.”
Nammo instead has been concentrating on improving its products by developing green ammunitions that are lead-free and also lack heavy metals such as strontium. “The Swedish and Norwegian armies have already standardized on these ammunitions,” said Mauritzson. “They fully meet military performance requirements as well as improving the terminal performance.”
Nammo has also developed infrared tracers in several calibers that are visible only to those using night vision devices so as not the give a position away to an enemy as well as the US qualified armor piercing ammunition which is Nammos most versatile round when it comes to effect in the target.
The Marine Corps is also interested in green ammo. The Corps has tested and procured the Army’s new M855A1 5.56 mm lead-free slug (LFS) round. “The Marine Corps has not determined which round will be used as a potential replacement for the basic M855 round currently in service,” said the Marine Corps spokesperson. “Part of our business case analysis will include user feedback on the SOST and the LFS. Currently, we are using the SOST only in Afghanistan because of its enhanced lethality performance against the current threat. For the same reason, we have procured small quantities of the Army’s LFS. We will take delivery of approximately two million of these rounds in the third quarter of 2010 for use in Afghanistan only.”
Meanwhile, FNH is in the process of developing a common receiver for one of its weapons, the company’s Mark 17 (SCAR Heavy), which normally shoots 7.62 rounds weapon, to enable it to shoot both 7.62 mm and 5.56 mm rounds. “It involves replacing a couple of parts such as the barrel, the bolt and the firing pin along with lowering the trigger module,” said Bailey. “You change out the magazine and you are able to run 5.56mm ammunition out of the same gun. We are talking about a truly modular dual caliber weapons system.”
The Mark 17 has been designed much lighter than the usual 7.62 mm rifle. Switching between a short barrel for the 5.56 mm ammunition and a long barrel for the 7.62 mm rounds doesn’t add much weight, according to Bailey. “The difference is between half a pound and a pound,” he said. “With current systems, we’re talking about four to five pounds difference.”
“This is something we have been working on for a while,” he added, “and I believe it is going to be right around the corner.” ♦