Review: LMT New Zealand Reference Rifle

New Zealand's military made it publicly known in May 2014 that they were hunting for a new rifle to replace the Steyr AUG and Australian-­made Austeyr F88 variant, the IW Steyr. The Steyr and Austeyr had been in service with the New Zealand Defence Force (NZDF) since 1988.

Eight firearms manufacturers submitted rifles for the solicitation, but the NZDF announced that Lewis Machine & Tool (LMT) won the $40-­million-­plus contract on August 12, 2015, for 9,040 rifles. The LMT CQB16 variant that won was designated the Modular Assault Rifle System-­Light (MARS-­L). These rifles were delivered in May 2017.

Unique about this contract is that all conventional units and the New Zealand Special Air Service (SAS) were issued this rifle. It is unusual in any military for both types of units to field the same rifle type or model.

There are several distinct features on LMT’s monolithic rail platform (MRP) that distinguish its rifles from others. For example, LMT’s upper receiver is the only patented, monolithic model available. The two traditionally separate components are the upper receiver and handguard. With LMT’s MRP design, these components are one, forged from a single, solid piece of aluminum. The monolithic design adds complexity to the manufacturing process, but it makes these rifles modular in a way that no other AR-­pattern rifle can ever be.

Two Torx-­head screws index and secure the barrel to the upper receiver. Each is torqued to 140 inch-­pounds (in.-­lbs.), so there is zero chance the barrel will come loose. A convenient LMT torque wrench that’s preset to 140 in.-­lbs. is available for $60. Loosening the two barrel screws (and removing the indexing screw) allows the shooter to remove the barrel out the front of the handguard for maintenance or to switch calibers or barrel lengths.

This feature is popular with military units because it allows for configuration of the rifle to meet multiple mission requirements and prolongs sustainability of serialized receivers. Rifles used in an urban environment can use the 10½-­inch barrel while those used in open terrain can opt for a 16-­inch barrel. Switching back and forth between those barrels takes no more than 3 minutes, if you take your time.

Market Ready 

LMT is now making the New Zealand Reference Rifle available to the U.S. civilian market. We benefit knowing that the design was successfully tested by multiple militaries, and collectors appreciate the opportunity to own a historical representation.

The same modularity that allows soldiers to adapt the rifle to different missions also allows recreational shooters and hunters to switch barrels for their different applications. Though the New Zealand Reference Rifle comes standard with a 5.56 NATO-­chambered barrel, LMT also offers 14 other barrels in different lengths and calibers ranging from 10½ to 20 inches and includes chamberings for .204 Ruger, .224 Valkyrie and .300 Blackout.

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LMT manufacturers barrels out of either stainless steel or chrome moly. The stainless steel barrels tend to have a slight accuracy advantage over the chrome-­moly models, but in G&A’s comprehensive testing of this platform a few years ago, we found both to be more accurate than what’s typically available.

The New Zealand Reference Rifle that Guns & Ammo obtained for evaluation is as close of a replica to what New Zealand adopted as any of us can own. From our study of it against an authentic issued rifle, this one only lacks the select-­fire trigger assembly and pictogram.

The barrel is chrome-­moly steel and measures 16 inches. Inside the bore is a 1:7-­inch twist. It utilizes a mid-length gas system and sports a bayonet lug. This is the most durable and relevant barrel currently fielded by any military.

LMT hammer forges its barrels, which work-­hardens the bore. As hammers beat the barrel around a mandrel to give it shape, the material next to the mandrel compresses and hardens. That extra-­hard bore helps to mitigate the heat and pressure that occurs when the rifle fires. A side effect is prolonged throat life. On top of the work-­hardened bore is a layer of chrome plating, which serves as another very hard layer of protection against unusual wear.

After the manufacturing process is complete, the barrel heads out for cryogenic treatment to relieve stress at the molecular level. Cryo’d barrels are frozen to such a low temperature that all of the steel’s molecules align. Any stressors imparted on the steel during manufacturing disappear. The absence of any stress in the steel makes each shot fired through the bore more consistent, and these rifles’ accuracy reflects this. G&A’s test rifle had one of the most accurate barrels we have ever tested in this platform.

Novel Design 

Also unique to these rifles is LMT’s use of a straight gas tube, which provides several advantages. A straight gas tube is much less likely to develop a knife-­edge where it joins with the bolt carrier’s gas key. Every other AR gas tube is bent in a couple of places so that it enters the upper receiver at the right height. These bends also make it very susceptible to having the tube enter the receiver at a slight angle, leading to the inevitable development of a knife-­edge. With that said, most commercial rifles are not fired enough for this to happen. Even if they were, the gas tube could also suffer from hot gases burning a hole at the bend and bleeding off gas necessary to cycle the action. LMT simply avoids these concerns with its straight tube.

The New Zealand Reference Rifle comes with LMT’s standard bolt carrier group (BCG), but the rifle delivered to the Kiwis were issued with either the standard bolt carrier or the enhanced bolt carrier.

The standard carrier has been in service for decades and is very similar to what’s found in most quality ARs. The enhanced carrier has several features that make the bolt much more durable. The redesigned carrier helps reduce the cyclic rate when fired full auto while simultaneously counteracting the overgassing that occurs when a suppressor is attached to the muzzle.

LMT’s enhanced bolt is made from a proprietary steel that only LMT uses. Most so-­called “enhanced” bolts on the market are made from 9310, a material superior to the military-­standard Carpenter 158. LMT claims to use a significantly better steel than 9310, which is also superior to Carpenter 158. LMT remains tight-­lipped about its material, but it is strong and easily recognizable by its chrome-­like finish.

“I can make you an AR bolt that I can guarantee will never break,” Karl Lewis, founder and president of LMT, told G&A. “Unfortunately, it would cost more than the rest of the rifle.”

The two areas where normal AR bolts fail are on the lugs at either side of the extractor and the cam pin hole. The enhanced carrier has an engineered cam pin path that allows the bolt to stay closed longer during extraction. This allows residual pressure inside the chamber to drop and reduces binding force on the bolt lugs, leading to a longer bolt life.

Ambi it is 

The NZDF encouraged LMT to develop a lower receiver that was as advanced as its MRP upper. LMT responded with a new receiver that’s completely ambidextrous. Ambidextrous charging handles and safeties can be found or fitted to just about any AR, but the LMT MARS-­L incorporates those into a receiver that also features a completely ambidextrous magazine release and bolt catch.

The magazine release is in the usual location on the right side of the rifle, yet you’ll find that its mirror image is on the left side of the rifle. Unlike a handful of aftermarket ambidextrous magazine releases, LMT machined a protective fence around the left-­side magazine release, too, to prevent unintentional activation.

The bolt catch is where it’s normally found on the left side of the rifle, and its counterpart can be found tucked behind the brass deflector on the right side of the rifle. The lever on the right side can be used to hold the bolt open or release it. It’s worth mentioning because we’ve found that not all so-­called “ambidextrous” bolt-­catch designs will release the bolt from the right side. Since it is tucked behind the brass deflector, it, too, is protected from unintended use while remaining within reach of the firing hand.

To own a proven and historically significant New Zealand Reference Rifle is an opportunity that comes with a suggested retail price of $2,700, placing it on a shelf that’s a too tall for many AR enthusiasts. However, for those who can reach, this certainly qualifies for shooters looking to find that one gun.

LMT continues to produce one of the most innovative barrel convertibles and high-­quality rifles on the market. The fact that the NZDF has decided to field them comes as no surprise to us.