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Marine infantry units replace some light machine guns with new automatic rifle
Marine infantry units soon may replace their light machine guns with new automatic rifles designed to help gunners move faster on assaults.
Weapons officials at Marine Corps Systems Command in Quantico, Va., are testing magazine-fed weapons from at least six gun makers in a search for a lighter alternative to the M249 Squad Automatic Weapon, which weighs close to 17 pounds unloaded.
At the squad level, “the biggest hindrance to being able to effectively fire and maneuver is the weight of the SAW,” said Patrick Cantwell, capability integration officer for the Infantry Automatic Rifle program at SysCom.
The winning IAR design — which the Corps wants to weigh no more than 12.5 pounds — could begin replacing the SAW in infantry squads as early as next year.
“We see this being the automatic rifleman’s primary weapon,” Cantwell said. “We obviously want it as soon as possible, but we are looking at sometime in 2009.”
The M249 has been in service with the Corps since the mid-1980s. The standard model weighs about 22 pounds when loaded with a 200-round belt of 5.56mm ammunition.
Despite its weight, the weapon spits out up to 750 rounds per minute, providing small units with a tremendous rate of sustained automatic fire.
Why the Army says no thanks
That’s why the Army, which also uses the M249, has ruled out a soldier version of the Marine IAR.
“We are not considering adopting an auto rifle for the infantry squad,” said Col. Robert Radcliffe, director of the Infantry Center’s Directorate of Combat Developments at Fort Benning, Ga.
Currently, Marine and Army infantry squads equip their fire teams with one M249 each. The difference, Radcliffe said, is that Marine squads have three fire teams, and Army squads have two fire teams.
“It’s really all about firepower. The Marine Corps has a 13-man squad; we have a nine-man squad — that’s a four-man difference.”
Army infantry officials, however, do want to find a replacement for the M249.
Since 2003, Army Materiel Command has stood up a robust refurbishing program that rebuilds worn-out SAWs to nearly new condition. But heavy operational use continues to take its toll on the M249’s performance, Radcliffe said.
“We recognize that we need to find another solution for the light machine gun in the squad,” Radcliffe said.
One option for replacing the SAW could be the MK46 — a newer version of the M249, redesigned for reduced weight and adopted by U.S. Special Operations Command in 2000. FNH USA makes the M249 and the MK46.
The MK46 has a fixed stock and 16.3-inch barrel. FNH removed features such as the magazine-feeding well, the tripod mount and the gas regulator, reducing the weight to 15.4 pounds unloaded.
The current M249 comes in two versions. The standard model features a fixed stock and a 20.5-inch barrel, and weighs in at 16.8 pounds unloaded. The paratrooper model has a collapsible stock and a 14.5-inch barrel, and weighs in at 15.95 pounds unloaded.
Like the M249, the MK46 has the same cyclic rate of fire of 750 rounds per minute.
“We are interested in the MK46,” said Army Maj. Thomas Henthorn, chief of the small-arms division at Benning, describing his brief impressions after shooting the MK46 there Aug. 6. “It does feel lighter than the SAW.”
Benning officials were quick to point out, though, that no decisions have been made on the MK46, and they offered no timeline for future testing.
Not going away completely
Marine officials are adamant the SAW is not going away. The M249 will remain in use by the rest of the Corps and will be available to Marine infantry commanders if they feel they need more firepower, Cantwell said.
The plan is to buy 4,100 IARs and reduce the number of SAWs in the Corps from 10,000 to 8,000, Cantwell said.
“We are still going to maintain SAWs in the company,” he said. “Only 2,000 SAWs will be replaced. The reminder will be kept as an organizational weapon for when commanders need them.”
The Marine Corps has been talking about the need for a lightweight IAR since 2001. But the program picked up momentum in early summer when Marine weapons officials began testing prototypes from several gun makers.
Corps officials would not say which companies are participating in the program.
But so far, officials from FNH USA, the current maker of the M249; General Dynamics Armament and Technical Products; Heckler & Koch; LWRC International LLC; and Patriot Ordnance Factory Inc. have confirmed they are competing for the contract.
Weapons sources also confirmed that Colt Defense LLC is participating in the IAR competition, but Colt officials would neither confirm nor deny the company’s participation.
One of the biggest changes Marine gunners will notice about the IAR is that it’s magazine-fed only, compared with the M249’s belted ammunition. The M249 also can fire standard-issue magazines.
Early on in the program, the requirement called for the IAR to use detachable, 100-round magazines. Now, Marine weapons officials are requiring only that it be able to run on the same 30-round magazines infantrymen use in their M16A4 rifles and M4 carbines.
Large-capacity magazines are not being ruled out for the future, but “we wanted everybody to have the same ammo and the same magazine,” Cantwell said, explaining that is easier to redistribute ammo when all the magazines are the same.
Army infantry officials maintain that switching from a 200-round belt to a 30-round magazine would cause Army squads to lose the high rate of fire they have with the M249.
“Volume of fire is important,” Radcliffe said. “The Marine Corps thinks it can get that out of a magazine-fed weapon. We don’t think the Army can.”
The M249’s sustained rate of fire is 85 rounds per minute. The requirement for the IAR calls for the weapon to fire 36 rounds per minute for 16 minutes, 40 seconds. The IAR also will be able to fire at a higher rate of 75 rounds per minute for eight minutes, Cantwell said.
Unlike the M249 — which relies on a quick-change, spare barrel to keep the heat down — the IAR will have no spare barrel, Cantwell said. It will rely on the slower rate of fire and other features to manage the heat, such as the requirement that it fire from both the open- and close-bolt position.
An open-bolt operation allows more air into the receiver and reduces the chance of a round cooking off in an overheated chamber, Cantwell said. The close-bolt mode offers more accurate fire and lowers the risk of a negligent discharge from the bolt slipping forward as a gunner maneuvers, he said.
Cantwell conceded that “there is a sacrifice of the volume of fire,” but the ability to move fast and fire accurately outweighs it. With the IAR, “you have a more maneuverable weapon that, we hope, allows the Marine [gunner] to be more effective.”
Marine infantry units soon may replace their light machine guns with new automatic rifles designed to help gunners move faster on assaults.
Weapons officials at Marine Corps Systems Command in Quantico, Va., are testing magazine-fed weapons from at least six gun makers in a search for a lighter alternative to the M249 Squad Automatic Weapon, which weighs close to 17 pounds unloaded.
At the squad level, “the biggest hindrance to being able to effectively fire and maneuver is the weight of the SAW,” said Patrick Cantwell, capability integration officer for the Infantry Automatic Rifle program at SysCom.
The winning IAR design — which the Corps wants to weigh no more than 12.5 pounds — could begin replacing the SAW in infantry squads as early as next year.
“We see this being the automatic rifleman’s primary weapon,” Cantwell said. “We obviously want it as soon as possible, but we are looking at sometime in 2009.”
The M249 has been in service with the Corps since the mid-1980s. The standard model weighs about 22 pounds when loaded with a 200-round belt of 5.56mm ammunition.
Despite its weight, the weapon spits out up to 750 rounds per minute, providing small units with a tremendous rate of sustained automatic fire.
Why the Army says no thanks
That’s why the Army, which also uses the M249, has ruled out a soldier version of the Marine IAR.
“We are not considering adopting an auto rifle for the infantry squad,” said Col. Robert Radcliffe, director of the Infantry Center’s Directorate of Combat Developments at Fort Benning, Ga.
Currently, Marine and Army infantry squads equip their fire teams with one M249 each. The difference, Radcliffe said, is that Marine squads have three fire teams, and Army squads have two fire teams.
“It’s really all about firepower. The Marine Corps has a 13-man squad; we have a nine-man squad — that’s a four-man difference.”
Army infantry officials, however, do want to find a replacement for the M249.
Since 2003, Army Materiel Command has stood up a robust refurbishing program that rebuilds worn-out SAWs to nearly new condition. But heavy operational use continues to take its toll on the M249’s performance, Radcliffe said.
“We recognize that we need to find another solution for the light machine gun in the squad,” Radcliffe said.
One option for replacing the SAW could be the MK46 — a newer version of the M249, redesigned for reduced weight and adopted by U.S. Special Operations Command in 2000. FNH USA makes the M249 and the MK46.
The MK46 has a fixed stock and 16.3-inch barrel. FNH removed features such as the magazine-feeding well, the tripod mount and the gas regulator, reducing the weight to 15.4 pounds unloaded.
The current M249 comes in two versions. The standard model features a fixed stock and a 20.5-inch barrel, and weighs in at 16.8 pounds unloaded. The paratrooper model has a collapsible stock and a 14.5-inch barrel, and weighs in at 15.95 pounds unloaded.
Like the M249, the MK46 has the same cyclic rate of fire of 750 rounds per minute.
“We are interested in the MK46,” said Army Maj. Thomas Henthorn, chief of the small-arms division at Benning, describing his brief impressions after shooting the MK46 there Aug. 6. “It does feel lighter than the SAW.”
Benning officials were quick to point out, though, that no decisions have been made on the MK46, and they offered no timeline for future testing.
Not going away completely
Marine officials are adamant the SAW is not going away. The M249 will remain in use by the rest of the Corps and will be available to Marine infantry commanders if they feel they need more firepower, Cantwell said.
The plan is to buy 4,100 IARs and reduce the number of SAWs in the Corps from 10,000 to 8,000, Cantwell said.
“We are still going to maintain SAWs in the company,” he said. “Only 2,000 SAWs will be replaced. The reminder will be kept as an organizational weapon for when commanders need them.”
The Marine Corps has been talking about the need for a lightweight IAR since 2001. But the program picked up momentum in early summer when Marine weapons officials began testing prototypes from several gun makers.
Corps officials would not say which companies are participating in the program.
But so far, officials from FNH USA, the current maker of the M249; General Dynamics Armament and Technical Products; Heckler & Koch; LWRC International LLC; and Patriot Ordnance Factory Inc. have confirmed they are competing for the contract.
Weapons sources also confirmed that Colt Defense LLC is participating in the IAR competition, but Colt officials would neither confirm nor deny the company’s participation.
One of the biggest changes Marine gunners will notice about the IAR is that it’s magazine-fed only, compared with the M249’s belted ammunition. The M249 also can fire standard-issue magazines.
Early on in the program, the requirement called for the IAR to use detachable, 100-round magazines. Now, Marine weapons officials are requiring only that it be able to run on the same 30-round magazines infantrymen use in their M16A4 rifles and M4 carbines.
Large-capacity magazines are not being ruled out for the future, but “we wanted everybody to have the same ammo and the same magazine,” Cantwell said, explaining that is easier to redistribute ammo when all the magazines are the same.
Army infantry officials maintain that switching from a 200-round belt to a 30-round magazine would cause Army squads to lose the high rate of fire they have with the M249.
“Volume of fire is important,” Radcliffe said. “The Marine Corps thinks it can get that out of a magazine-fed weapon. We don’t think the Army can.”
The M249’s sustained rate of fire is 85 rounds per minute. The requirement for the IAR calls for the weapon to fire 36 rounds per minute for 16 minutes, 40 seconds. The IAR also will be able to fire at a higher rate of 75 rounds per minute for eight minutes, Cantwell said.
Unlike the M249 — which relies on a quick-change, spare barrel to keep the heat down — the IAR will have no spare barrel, Cantwell said. It will rely on the slower rate of fire and other features to manage the heat, such as the requirement that it fire from both the open- and close-bolt position.
An open-bolt operation allows more air into the receiver and reduces the chance of a round cooking off in an overheated chamber, Cantwell said. The close-bolt mode offers more accurate fire and lowers the risk of a negligent discharge from the bolt slipping forward as a gunner maneuvers, he said.
Cantwell conceded that “there is a sacrifice of the volume of fire,” but the ability to move fast and fire accurately outweighs it. With the IAR, “you have a more maneuverable weapon that, we hope, allows the Marine [gunner] to be more effective.”
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