Mossberg MMR

posted on June 14, 2012
Mossberg’s first venture into the AR-15 market, the MMR is a solid platform at a price sure to entice many modern shooters. With a host of desirable features from muzzle to buttstock, it immediately puts the company on the AR map.

Modern: characteristic of present and recent time—not ancient or remote, contemporary. There's no denying the AR-15 and its variants are contemporary firearms. Right now, they're the most popular sporting long arms on the planet. But they are not new. The AR-15 and the cartridge it made famous—the .223 Rem.—have been around for 50 years. The AR-15 is, however, new to Mossberg, hence the company's decision to call its latest long gun the Mossberg Modern Rifle (MMR). (For a complete gallery of photos of the MMR, go here.)

I'm not the most politically correct bear on the block. I like to call things what they are; a rifle is a rifle and an AR is an AR. So, calling a 50-year-old rifle design a modern sporting rifle makes about as much sense to me as calling a hammer with a fiberglass handle a modern nail driver. However, I'll make a semi-exception in Mossberg's case. The company is well known for the manufacture of shotguns and traditional longarms, so the endeavor of building ARs is indeed a "modern" move.

Mossberg is offering two versions of its MMR. One is configured as a hunting rifle and the other—the subject of this review—is designed for the tactical market, which includes military, law enforcement, competitive shooters and civilians who want a Katrina rifle. This is not a new market for Mossberg. It's true, the company has a rich heritage in hunting, but Mossberg has been supplying the military, law enforcement and civilians with tactical shotguns for many years.

With a quad-rail handguard surrounding its free-floated barrel, the MMR provides both great versatility and fine accuracy.

The company's decision to offer an AR makes perfect sense, especially a tactical AR-style rifle. This is partly because it allows the company to engage various law enforcement customers by offering not just a tactical shotgun, but a patrol/tactical rifle. Furthermore, by engaging in the manufacture of an AR, Mossberg becomes more mainstream and much better prepared to moveinto the future with similarly configured firearms.

The challenge for Mossberg was how to enter a market already saturated with various takes on the AR design and be competitive.

It seems everyone, including the goober working the counter at the local stop-and-rob, is offering an AR, so appealing to loyal Mossberg customers was not enough. To be successful with this project, Mossberg needed an AR designed to attract new consumers.

Mossberg's MMR operates on the direct-gas-impingement system. The company lists eight variations of the MMR, but in reality there are only two major distinctions: it is available with or without sights and with or without an adjustable buttstock. Regardless of which version you choose, the barrel will be 16.25 inches long.

A Stark SE-1 pistol grip adds comfort and controllability, but the author found its flared backstrap made actuating the safety lever with the strong hand difficult.

The MMR is compatible with most mil-spec aftermarket components. Its major parts are manufactured by Mossberg and/or exclusive Mossberg vendors in the United States. The receiver is a 7075-T6 aluminum forging and the bolt is manufactured from Carpenter 158 plastic-mold steel—which is a case-hardened mold steel with exceptionally high strength—and electric-furnace melted, which provides unvarying lot-to-lot uniformity.

Both the bolt and barrel are 100-percent high-pressure tested with either military M197 or SAAMI-equivalent proof ammunition, and both are 100-percent magnetic particle inspected. The barrel is manufactured from AISI 4140 carbon-alloy steel and is chambered for the 5.56 NATO cartridge. Its receiver extension is also mil-spec and measures 1.14 inches in diameter.

The MMR's rifling is button broached with a 1:9-inch RH twist and the muzzle is threaded with a standard 1⁄2x28 thread. All Tactical MMRs are fitted with a removable A2-style flash hider and a carbine-length gas system. Its barrel extension contains M4 feed ramp cuts that extend into the upper receiver. MMRs have a dustcover, but they are not equipped with a forward assist. In addition, the barrel is free floated and surrounded by a quad-rail handguard.

The fire-control group uses .154-inch-diameter pins and the trigger is a standard, single-stage AR model. MMRs come with a 3-ounce buffer and the bolt carrier is the AR-15 SP1 style, which is close to the original Stoner design.

My first exposure to the Mossberg MMR was during a hunt in Oregon. A varmint hunt may not be the best place to sort out the serviceability of a tactical rifle, but since ground squirrels and rock chucks were in abundance, the opportunity to do a lot of medium-range shooting in a field environment was ever present.

I hunted with the MMR off and on for three days, shooting critters at ranges out to nearly 300 yards. In all, I fired in the neighborhood of 400 rounds through several different MMRs. Functioning was flawless and accuracy seemed sufficient. Several 300-yard-plus hits on the little vermin were registered.

Shortly after returning home, Mossberg supplied me with an MMR to abuse at my leisure. First, I mounted a Vortex 4-16X Viper riflescope in Talley Tactical Rings. I picked three factory loads ranging in weight from 40 to 69 grains for accuracy testing. Based on five, five-shot groups, the rifle demonstrated enough precision to expect five-shot groups to be in the 1- to 1.5-inch range at 100 yards This is not match-grade accuracy but, based on the ARs I've tested from various manufacturers, it is average or perhaps a bit better.

Next, I removed the riflescope and installed the iron sights that ship with the rifle. These attach directly to the flattop upper receiver and the quad-rail handguard with a thumbscrew. The front sight is adjustable for elevation and the rear sight is adjustable for both elevation and windage. I pushed the MMR through a variety of drills to see how it functioned during sustained rapid fire and from various field shooting positions.

After 90 rounds, I installed a 1-4X Trijicon AccuPoint riflescope along with a set of XS Sight Systems' new Angle Mount Sights and proceeded to run through the drills again, alternating between using the riflescope and XS sights. The Mossberg MMR never hiccupped while dumping more than 200 empty cases on my range. I did, however, have two complaints.

A removable rear sight ships with the MMR and mounts to the top rail. It is adjustable for both windage and elevation.

When it comes to evaluating AR-style rifles from various manufacturers, all we can really do is nitpick. Over the last year I've field-tested 13 different AR-style rifles, and they all functioned perfectly. It's no surprise, really—after 50 years of perfecting this design, you'd expect manufacturers to have it right. Admittedly, some shot more accurately than others, but even in the accuracy category, none of the rifles I tested were a dog that wouldn't hunt. With the Mossberg MMR, my nitpicking is minimal, but in the interest of staying objective, here are my dislikes.

Due to a portion of the Stark Equipment pistol grip that extends back over the web of the thumb and first finger, I was unable to engage the safety without altering my grip. This is indeed a very comfortable pistol grip to hold—perhaps the most comfortable I've had in hand. It even has a storage compartment inside. Depending on your hand size, you may or may not have the same issues with operation of the safety lever.

My second complaint deals with the quad-rail handguard. It is wider than I like, and the edges of the Picatinny rail are sharp. Go ahead and make jokes about gunwriters with soft, lotiony hands and how we need to wear gloves to shoot real guns. You won't hurt my feelings. But, for serious, down-and-dirty work, you'll want to wear gloves or dress the rail up with a Magpul Ladder Rail Panel, even if you're a steel-driving man.

Lastly, and this is not a complaint on my part, the Mossberg MMR does not have a forward assist. As I mentioned, ARs have become so reliable that unless you are in a seriously dirty environment, a forward assist is probably not needed. In all the firing I conducted with the Mossberg MMR, even in the Oregon dust, I never needed any assistance chambering a cartridge. Still, for truetactical operators this is a feature many demand.

As for the very comfortable pistol grip, if it prohibits your operation of the safety you can by all means swap it out with one that does not. And, as far as the handguard is concerned, you can dress it up as needed. With regard to the forward assist, there is no fix. If it is something you insist on, you'll have to look elsewhere.

The Mossberg MMR does bring a new realm of consumer attention to the company, and it also provides its loyal fans with an AR option. Those who choose the Mossberg MMR might also take the opportunity to discover the other centerfire, rimfire and shotgun offerings the company has available, and for Mossberg that is a good thing.

The AR has become the 1911 of the rifle world. Like the 1911, there are so many options and variations on the platform, because a perfect AR or 1911 only exists in the mind of individual shooters. The ultimate AR's configuration will be based on how they plan to use the rifle and what features they consider relevant based on their experiences. Mossberg has brought AR enthusiasts another reliable and viable option to consider.

Manufacturer: O.F. Mossberg & Sons; (203) 230-5300,
Action Type: Gas-operated, semi-automatic
Caliber: 5.56 NATO
Capacity: 10 to 30 rounds, depending on model
Receiver: 7075-T6, black anodized aluminum
Barrel Length: 16.25 inches
Stock: Six-position, telescoping
Rifling: 6 grooves; 1:9-inch RH twist
Sights: Removable, adjustable front and rear
Trigger Pull Weight: 4.2 pounds
Length: 36.5 inches (extended), 32.5 inches (collapsed)
Weight: 7 pounds, 8 ounces
MSRP: $921


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