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Army aims for positive improvements with M4A1+

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Army aims for positive improvements with M4A1+
By Kyle Jahner, Staff writer 9:33 a.m. EDT July 7, 2015

While the Army continues to upgrade existing M4s to the deadlier, more reliable M4A1, Army leaders have mapped out a whole new list of additional improvements to the legacy rifle.

The Army has requested from industry new enhancements to create what's called an M4A1+. The "plus" components would give the M4A1 an extended Picatinny rail, a floating barrel to enhance accuracy and an optional sniper-style single-stage trigger.

"We're always trying to modernize and upgrade the weapon to make sure we've got the best weapon available," said Lt. Col. Terry Russell, project manager for Individual Weapons at Picatinny Arsenal. "There are no deficiencies that we're trying to correct; we're just trying to make sure it remains a premier weapons system."

Earlier this year, the Army asked industry for examples of existing weapon upgrades that could be applied to the M4A1.

Russell said the desired enhancements should require more research and development for the M4A1, used by special operations since 1994.

"We are very confident that these already do exist, or that (companies) can develop them for us in short order," Russell said.

The solicitation stipulated that all of the components "seamlessly integrate with the current M4A1 Carbine," and "without negatively impacting or affecting the performance or operation."

The Army's request to industry would allow for the M4A1+ to weigh slightly more than the M4A1. Unloaded and without accessories the M4A1+ specs say it should weigh less than 8 pounds. The unloaded M4A1 weighs 7.74 pounds.

Here are eight key components that would give your M4A1 that added "plus."

1. Shoot with a straight elbow: The requested forward Picatinny rail, according to the Army specs, would be 12 inches long. That makes it about four inches longer than the current standard, and with reason.

The M4 and M4A1 are designed to be held with a bent front elbow. But many soldiers utilize a technique in which they extend their arm and lock their elbow for better stability. That technique is a bad idea on current carbines because of a shorter rail, Russell said. For most shooters, extending the forward arm would put the hand past the end of the rail and require the shooter to hold the barrel instead — a good way to burn that hand.

2. Attach more gear: Along with hand placement, the longer rail would allow soldiers to attach more enablers to the weapon, such as laser sights and pointers, forward grips, bipods, optics and lights.

"Right now, there's limited space," Russell said. "This allows you to put more than you are currently able to put on them."

Russell said part of the reason for seeking enhanced mounting capacity comes with an eye toward the future: the Army's ongoing development of a rifle fire control system.

The Army remains a few years away from a working prototype that meets its requirements, Russell said. But eventually, the system will effectively adjust the crosshairs in a scope to account for factors like distance, wind, humidity, barometric pressure, and ammunition characteristics. The longer rail of the M4A1+ will better facilitate the new tool, which Russell said the Army hopes will compare in size to today's optic systems.

3. Floating for accuracy: Encased in the new extended rail would be a floating barrel. In other words, the wrap-around rail would not touch the barrel.

A rifle's barrel vibrates naturally when it fires, and altering the harmonics on the barrel can impact accuracy. When a rail is attached to the middle of the barrel as it is now, forces exerted on the rail do just that as they are exerted on the barrel. Forces can include the rigidity of the rail itself, weight of enablers, the pull of a sling mounted to the rail, or a tight grip by the forward hand on the rail.

"A soldier holding it with a rigid grip can have an effect, and that causes some accuracy degradation," Russell said of an accessorized, non-floating barrel. "By having the floating barrel on there, it takes all those things out of the equation, which allows better accuracy."

4. Removable sights: The Army, Russell noted, wants to take weight off the soldier wherever it can. That's part of the reason the call to industry specifies removable front and rear iron sights.

That feature would also allow for lower-profile enablers (that don't stick out as much). That would make for a less-bulky accessorized rifle with a lower center of gravity. It also would reduce the silhouette signature, Russell said, making it harder to spot.

For soldiers who want the sights, there will still be a small, fold-down front and rear sight that can clip to the Picatinny rail, Russell said.

5. Better accuracy: In terms of system accuracy, the specs require a 5-inch mean radius from 300 meters, throughout barrel life. That means shots average no more than 5 inches from the target.

Additionally, the Army hopes the weapon can limit the extreme spread of 5 inches at that distance and 10 inches at 600 meters, with a 90 percent probability. That goal, listed as "desired" rather than "required," means 90 percent of shots fit into a circle 5 inches in diameter (a 2.5-inch radius) at 300 meters, and a circle twice as wide at 600.

6. Flash suppressor. The specs request an improved flash suppressor to reduce both day and night firing signatures. That new muzzle brake, Russell said, should make a fired M4A1+ a little more difficult to see and hear.

The suppressor should, according to specs, include a blank firing adapter compatible with M200 ammunition. (The adapter is the muzzle-blocker used in blanks-based training to minimize injury should the gun accidentally fire a live round).

7. Optional sniper trigger: One modification won't go on every M4A1+, but the squad marksman will appreciate it.

A specialized trigger will offer sniper-like sensitivity, Russell said. Current carbines have double-stage triggers, with some slack to pull before the weapon fires. The specialized trigger module will be single-stage: the gun will fire basically once the trigger moves.

"It's very sensitive to the touch. When pulling the trigger you don't have to pull it as hard, which allows you to maintain accuracy on the target," Russell said. "At shorter distances it (the difference in accuracy) is not that significant, but at longer range, it becomes more significant."

Specs call for a "single-stage trigger, free of creep, with consistent trigger pull weight" of 4-5 pounds. It should work on both semiautomatic and automatic settings.

The trigger module would be procured separately, meaning a different company may produce it, rather than the one that supplies the rest of the upgrades.

8. Stealthier: To reduce visual detection, the Army wants the colors of the new parts to be "neutral (non-black) color" of a "rough, dull, non-reflective, coating/finish that retains paint." The request specifies a brownish color, one between Coyote 498 and Light Coyote 481.

Even more M4 improvements

In addition to the M4A1 and M4A1+, the service is weighing whether to pursue even more improvements via its Soldier Enhancement Program. SEP is designed to test off-the-shelf equipment that could improve a soldier's combat effectiveness. Many of SEP's ideas come directly from soldiers themselves. Leaders of SEP are considering testing the following commercially available improvements for the M4 platform.

• A better tool to clean the bolt, carrier and firing pin.

• Picatinny attachments that could insulate soldiers' hands from heat and protect accessory wires so they don't get caught on anything.

• A heat resistant rubber, plastic shield or other polymer shield that can wrap around the pistol grip to insulate heat and optics to provide protection.

• An integrated arms system including advanced fire control technology, with target tracking, environmental sensors, automatic ballistic calculation, heads up display and networking.

• A hand-guard system that weighs 20 percent less and is thermally insulated.

• A device that slightly raises the rifle combat optic and moves it back, improving ease of use.

• A device that allows soldiers to zero their weapons (calibrate the sights so it accurately indicates where the bullet will hit) in any environment without live fire.

• An ambidextrous, lightweight, rugged sling-mount adapter. The socket attaching a carrying strap to the gun should be mountable to a Picatinny rail in seconds and easily adjusted for comfort.

• A device to fill the gap between the trigger guard and the pistol grip, one that cushions the knuckle and prevents finger abrasions.

Got an idea to improve the M4? Send your feedback to: kjahner@militarytimes.com


Here’s The Tech The Army Wants To Use To Upgrade The M4
Christian Beekman  By Christian Beekman  on July 8, 2015

The Army is looking to buy off the shelf.
Several months ago, the Army’s Project Engineering Office for Individual Weapons announced it was looking for sources to pursue what it called M4A1+, a series of upgrades to the M4A1 carbine that will be sourced from commercially existing components.

Lt. Col. Terry Russell, the project manager for Individual Weapons at Picatinny Arsenal, New Jersey related the impetus for the program in an Army Times story: “We’re always trying to modernize and upgrade the weapon to make sure we’ve got the best weapon available … There are no deficiencies that we’re trying to correct; we’re just trying to make sure it remains a premier weapons system.”

Task & Purpose has covered upgrading the M4 with commercial parts before, but Russell’s remarks have clarified the scope and direction of the M4A1+ program; they also indicate changing attitudes regarding carbine gunfighting in the Army.

One of the most significant upgrades would be a new modular railed forend. The Army has specified that the rail be at least 12 inches long. The longer rail would allow soldiers to accommodate the thumb-over-bore shooting technique, which straightens the elbow of the support hand and allows the shooter to better manage recoil. While thumb-over-bore has been around for decades, the technique has entered the shooting mainstream. The Army also wants the rail to be free-floated, eliminating outside forces like sling pressure and the shooter’s grip that affect the barrel’s accuracy. The Army’s acknowledgement of current shooting techniques and technology with the M4A1+ design is welcome sign of evolving thinking regarding the infantry rifle.

Over the past 15 years, accessories like lights, infrared aiming lasers, and foregrips have become a common sight on infantry rifles. This has added weight to the carbine, while also crowding the limited space on the current issue seven-inch long Knight’s Armament rail. The Army has therefore asked that the new rail feature a continuous length of Picatinny rail in the “12-o’clock” position, with modular rail segments of varying lengths for the other sides of the rail. This saves weight, slims the profile of the handguard, and allows the user to mount only the rail space he needs.

There are plenty of products on the market that fit this description; including the Knight’s Armament URX, Geissele Automatics Super Modular Rail and the Centurion Modular Rail. It’s understandable why the Army would retain the Picatinny rail standard; virtually all the accessories it issues to troops use it. But the Army could plan ahead by adopting one of two new attachment standards. Finally, the Army wants the rail to be a more neutral coyote tan color, in order to disrupt the outline of the carbine and impede visual detection.

The first is an open-source system called Keymod, which features a key-shaped chamfered slot and nut system. Introduced in 2012, the open-source nature of the system has ensured that many railed forends and accessories are now on the market. M-LOK, developed by well-known gun accessories company Magpul Industries, uses a T-nut and lug system. The system is licensed freely by Magpul in order to maintain manufacturing standards. M-LOK is fairly new, so there are less rail and accessory options available. Both Keymod and M-LOK allow accessories to be directly mounted, saving weight, and allowing for a tighter overall profile that aids in weapons manipulation. Both systems also feature legacy Picatinny rail adapters, so the Army could adopt either one, and replace accessories with the appropriate direct-mounted version as time goes on.

The M4A1+ solicitation provides a goal for improved accuracy: “The system accuracy for the M4A1+ shall be 5 inches mean radius at 300 meters throughout barrel life (required) and shall be 5 inches extreme spread at 300 meters throughout barrel life with .9 probability (desired) and shall be 10 inches extreme spread at 600 meters throughout barrel life with.9 probability (desired).”

This is actually a pretty ambitious accuracy goal, considering the M4A1+ program does not alter the stock barrel. Free-floating rails will enhance the accuracy of the M4A1, but the barrel and ammo will also contribute heavily. As such, the Army has label this specification as “desirable,” rather than required.

The extended rail means that a new low-profile gas block is required, along with the option of removable front and real sights. The increasing prevalence of optics on infantry rifles means that more traditional iron sights are less important. Removing them shaves off a little more weight from the weapon. Still, the Army plans to purchase flip-up irons sights as part of M4A1+, for those without optics or who desire a backup sight to their primary optic. Dozens of companies produce these parts; so the Army will be spoilt for choice.

A new flash suppressor has also been requested, with the goal being “to reduce the day and night firing signature and night vision device blooming effect of the weapon to be less than the current carbine without loss in system performance.” The only other requirement is that it be compatible with is a blank-firing adapter for training purposes. It seems the Army opted to forgo the option of brakes and other hybrid muzzle devices, likely due to concerns about hot gas and debris from muzzle blasts hitting those adjacent to the shooter in range and close-quarters combat settings. Surefire, Advanced Armament Corporation, and B.E. Meyers have all provided flash hiders to special operations units in the past; they’re also popular on civilian AR-15s.

Perhaps the most surprising request is for an internal change to the M4A1. The Army wants to outfit M4A1 being used as designated-marksman rifles with precision triggers that feature less trigger pressure and travel. Russell explains the advantages of such a trigger: “It’s very sensitive to the touch. When pulling the trigger you don’t have to pull it as hard, which allows you to maintain accuracy on the target … At shorter distances it (the difference in accuracy) is not that significant, but at longer range, it becomes more significant.” Aftermarket triggers like this are becoming popular in civilian shooting circles; Geissele Automatics and ALG Defense are well-known options.

There are several other requests, like quick-detach sling mounts and ambidextrous charging handles. The Army also has its Soldier Enhancement Program, which is looking to field improvements like better cleaning equipment and zeroing tools. Some other commercial upgrades the Army might want to pursue include better accessory switches and more ergonomic pistol grips. One note of concern is that the Army wants to source all these upgrades save the trigger from the same vendor. This could potentially limit the options the Army has for upgrades, and prevent the best possible parts from getting selected. But the fact that the Army is pursuing these upgrades at all is a welcome indication that the M4A1 carbine will be brought up to the latest standards as a modern weapon system.