If the Marine Corps' top marksmanship experts get their way, Marines are going to get a rifle retooled with an array of upgrades that will make them deadlier shooters. They recently directed the study of a number of significant changes to the service's weapons, ammunition, shooting curriculum and ranges and have approved new competitions.

Most eagerly anticipated are recommendations to study overhauling M16A4 rifles and M4 carbines with a host of new features, including a new trigger and barrel, all of which will be a hot topic at the next Combat Marksmanship Symposium in October.

The lines of pursuit — the product of the this year's Combat Marksmanship Symposium held here in Quantico — hold a common theme, according to leaders at Weapons Training Battalion Quantico. They are designed to make Marines deadlier in combat and provide them the tools and training to dominate the battlefield whether in the sands of the Middle East or the jungles of the Asia Pacific region.

"I thought the most important thing was not to look at the short term," said Col. Tim Parker, the commanding officer of WTB Quantico and the Marine Corps' marksmanship proponent.

"I didn't want a range or weapon for today. I wanted one for 2050 to 2100. Extrapolating what we have in Expeditionary Force 21, it was about how we fight this century. I want the symposiums looking out further," he added.

A 'new' service rifle

Current M16A4 rifles and M4 carbines could get a significant overhaul with mostly inexpensive components already available to consumers. The upgrades would drastically improve accuracy and function without incurring the expense of procuring an new rifle.

Those updates could include a free-floating barrel, rifle compensators, new reticles for the Rifle Combat Optic, more ambidextrous controls and a new trigger group. With significant advancements in rifle technology for the civilian shooting market over the past two decades, those are all features commonly seen on competition rifles and those carried by elite operators.

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It's a novel and mostly inexpensive approach to improve the tried-and-true inventory of standard service rifles even as defense budgets continue to shrink and the service's procurement and sustainment programs compete for money. Small arms have often taken a back seat in recent years to big-ticket platforms like the F-35 Joint Strike Fighter, Amphibious Assault Vehicle modernization and the procurement of the next generation ship-to-shore troop transport, the Amphibious Combat Vehicle 1.1.

In 2013, as the military's manpower drawdown got underway and the services scrambled to realign budgets and personnel, Brig. Gen. William Mullen, head of the Corps' Capabilities Development Directorate, said small arms were sufficient — even if not ideal. "The weapons we have right now are working pretty good," he said. "They aren't perfect. You talk to Marines and get 20 different opinions about our weapons. But they are doing the job."

But the Corps' top gunners have an eye toward giving current rifles a makeover that would make them shoot like a next-generation weapon. Over the next seven to eight months they will study proposed upgrades by surveying the commercial market, testing products on the range and estimating potential costs before presenting a recommendation at the next marksmanship symposium. The symposium's working groups will make final recommendations based on research now underway and hand those to the Corps' top general, Commandant Joseph Dunford, for a final decision — a process that can take several more months.

Comps. Among the simplest potential upgrades is the addition of a compensator, or "comp" on the rifles' muzzles in place of the decades-old birdcage flash suppressor.

"The best shooters in the world have comps. Why?" said Chief Warrant Officer 3 Tom Layou, the battalion gunner at WTB Quantico. "It is hardest to hit multiple and moving targets and compensators manage that recoil."

While flash suppressors reduce a rifle's visual signature as shots are fired to help conceal the exact location of a shooter on the battlefield, compensators are designed to improve a firearm's handling. There are some hybrid devices on the market, but most focus on either reducing visual signature or managing recoil, which means officials must weigh the tradeoffs between handling and concealment. It should be noted, however, that flash suppressors do not entirely cloak a Marine's position, especially at night. Both flash suppressors and comps work by altering how combustion gasses from the propellant that drives a bullet through the barrel and then escape the muzzle. A flash suppressor disperses burning gasses to reduce the intensity and brightness with which they combust, while a compensator redirects gasses to reduce muzzle flip and counteract felt recoil.

For a Marine, a compensator would allow for faster follow-on shots since reduced recoil means each shot would lessen the disturbance to sight alignment and sight picture. That helps when several shots are needed in quick succession to strike moving targets or put down an enemy who continues to fight after being struck by the first round.

There are downsides, however.

"The positive is great shooting. The negative is the noise, especially inside," Layou said.

Because compensators typically direct a large amount of expended gas rearward and to the sides, there is a threat that the intense noise and overpressure will be hard for Marines to the left and right of a shooter to tolerate. Those effects are magnified indoors, which means they would be especially unpleasant and potentially injurious when clearing a building or compound.

Barrels. The adoption of a barrel that would increase accuracy is another significant but more expensive upgrade under consideration. Greater accuracy could be achieved several ways including the use of a heavier barrel, according to Layou. But the most obvious and common way to achieve greater accuracy is the use of a free-floating barrel like those used by most hunters and competitive shooters.

Standard-issue M16A4s and M4s use hand guards and rail systems that are directly connected to the barrel. As a result, any force exerted on an accessory like a rifle sling used to achieve greater stability also exerts force on the barrel. That can ever so slightly bend or pull the barrel off center relative to zeroed optics. The movement can translate into big variances over distance. The longer the shot, the further the external pressure exerted on the barrel will throw it.

A free floating barrel is achieved by using a hand guard and rail system that does not contact the barrel at any point. So any force exerted on a sling or other rifle-mounted accessory attached to the rail system does not translate to the barrel which contacts the rifle at only one point – the upper receiver. That ensures the barrel and optics which are also mounted to the upper receiver point in precisely the same direction.

"Free floating barrels have been seen in the competition world since the '90s," said Layou. "In combat you are not able to apply the same sling tension every time. You are shooting in different positions at different targets. So it's not a training solution, it is a material solution needed to reduce barrel flex."

If the need for more accurate barrels is approved in October after weighing factors to include cost, experts will write a requirement to improve accuracy. But it would be left to Marine Corps Systems Command to determine how to meet those specific requirements, which could also include the use of a heavier barrel, said Parker.

A free floating barrel could improve the M16A4 from a 4.5 minute-of-impact rifle to a 2 MOI rifle, putting it on par with the M27 Infantry Automatic Rifle, which uses a free floating barrel, said Chief Warrant Officer 5 Vince Pope, the Marine gunner who directs the Marksmanship Doctrine and Programs Management Section at Quantico. That means the rifle will go from being accurate within a tolerance of 4.5 inches from its point of aim at 100 yards to just 2 inches. When engaging a target at an M16A4's maximum effective point target range, which is nearly 660 yards, according to Colt Defense, that 4.5 inches with the current barrel compared to 2 inches with a free floating barrel translates into nearly 30 inches compared to about 13. That can be the difference between still hitting an enemy in the torso and hitting him in the thighs or knees.

Optics. To help Marines better hit their target, experts at WTB Quantico are also deliberating an improved Rifle Combat Optic that would feature a reticle like that seen in the Squad Day Optic currently issued for use on the IAR.

Both are manufactured by Trijicon, but use a slightly different pattern. The RCO features a chevron-shaped reticle that covers the target with the point of impact at its apex. It works fine, said Parker, but the SDO reticle works better.

The SDO uses a semi-circle with a dot at its center. It is more intuitive for the human eye and doesn't obscure the target nearly as much, Pope said. At 300 or more yards, the chevron reticle nearly entirely covers a torso-sized target while the SDO reticle encircles it so a Marine can still see what he is hitting.

Because the reticle is already in use, it would be easy and inexpensive to swap them if it is done as RCOs are shipped back to Trijicon for routine depot-level maintenance, according to the leadership at WTB Quantico. That would require some minor modification of current contracts with Trijicon, however.

Triggers. The M16A4's and M4's current triggers will also be reviewed.

"Rule number one in marksmanship," said Layou, "is stay consistent."

Consistency offers accuracy from shot to shot. But the service's current trigger violates that cardinal rule with three distinct trigger pulls felt on a rotating basis. In other words, it takes a different amount of force to break the trigger the first, second and third time it is pulled. The fourth trigger pull is again, like the first. That is the direct result of the rifle's select-fire capability that allows it to be set on safe, semi-automatic, or three-round-burst.

This could potentially be one of the more expensive upgrades simply because it would require the most research and development. "No engineer has cracked the code," Layou said. That means the service would have to draft a requirement and then turn to industry to develop a new trigger group.

The other alternative Layou said, is to reconsider the three-round burst capability. Is it needed? Might a precision semi-automatic trigger with a smooth, consistent trigger pull be a better fit? Those are questions that will be answered in the year ahead.

Southpaws. The last upgrade being considered is retrofitting rifles for left-handed Marines. About 10 percent of Marines are left handed, said Parker. Those Marines already enjoy ambidextrous magazine releases and select-fire levers, but not charging handles or bolt catch releases. As a result, southpaws must manipulate their weapons more to perform basic functions. That costs precious moments in battle.

Ambidextrous charging handles and bolt catch releases are commonly available on the civilian market for less than $100 and less than $30, respectively. So while the change would only affect roughly 10 percent of Marines, it would be one of the easiest and cheapest upgrades.

Better ammo

The best rifle in the world is little more than an expensive club without the ammunition to match. So experts at WTB Quantico are working toward adopting the AB49 Special Operations Science and Technology 5.56mm cartridge as the service's standard round.

SOST rounds, adopted for use by Marines in the war zone beginning in 2010, provide better ballistics than standard A059 5.56 ball ammunition as the bullets travel from muzzle to target and have more devastating effects once they impact the enemy.

When striking a person, a SOST round leaves a larger primary wound cavity, meaning enemy fighters are likely to bleed out faster. Short of a direct hit to the central nervous system, that is the only reliable method of incapacitation, Layou said.

The plan is to continue using SOST rounds for deployed units, while using old ball ammunition exclusively for training and putting a halt to future purchases, said Maj. Devin Blowes, WTB Quantico's operations officer. Under that plan, the service would exhaust all current inventory of old ball ammunition within seven to 10 years. And at that point, all new purchases would be for SOST rounds, which would then be used for training and combat.

The service needs congressional approval to make the change, but Parker is optimistic, saying Congress has given favorable consideration to past ammunition requests. Given that SOST rounds provide better performance without additional cost, he doesn't foresee resistance from lawmakers.

Hollow-points. For pistols, the service will investigate the potential adoption of hollow-point rounds. Personnel at WTB Quantico recently visited the FBI's ballistic lab, also aboard Quantico, where they saw demonstrations of ball and hollow-point ammunition. Ball pistol ammunition, like that now carried by Marines into combat, failed to expand after hitting ballistic gel meant to replicate the human body. That means the wound inflicted is less likely to be lethal than hollow points, which expandand leave significant primary wound channels that result in rapid blood loss.

The adoption of better pistol rounds becomes increasingly important as Marines look to a future where they will be more likely to operate in highly urbanized littoral areas. Because of confined spaces in small alleys, rooms and halls, Marines could find themselves relying on pistols more than ever, said Layou.

Holster study

Top pistol experts will also consider new authorized ways to wear the Marine Corps' SERPA Level 2 Tactical Holster, adopted in 2011 and produced by Blackhawk.

One appeal of the holster is its modular design that allows it to be quickly moved from one mounting bracket to another on a belt, drop-leg holster or a MOLLE-attached bracket. But for safety reasons, it is authorized only for wear on the hip or thigh.

Despite that, some Marines in the war zone do wear holstered pistols on their chest because it is more convenient for those who operate in vehicles.

It can be difficult to access a pistol on your hip when in the confines of a vehicle. In some cases a Marine may not actually fit into a blast seat while wearing a hip holster, said Capt. Brian Basil, the headquarters company commander and marksmanship range and facility campaign plan manager at WTB Quantico.

While some specialized units, including Marine Corps Forces Special Operations Command, may also wear chest-mounted holsters, they are not generally authorized for wear in that location because drawing from the chest is similar to a "cross-draw," in which one is likely to flag their own arm and fellow Marines down the firing line with the muzzle of their weapon. That poses significant safety challenges during live-fire training, experts agreed.