The Modular LMT MRP: The Rifle for Anything

The LM308MWS can go from sniper rifle to assault rifle with ease and the rapid fire of 20 rounds provide ample accurate cover fire.

The lower receiver would use the standard SR-25 steel magazine but would eventually primarily use the Magpul LMag.  The lower receiver has an ambidextrous magazine catch as well as selector lever. The receiver is equipped with a LMT SOPMOD buttstock which has six positions.  This stock is standard equipment on U.S. Navy MK18 rifles and all SOCOM M4A1 carbines as part of the SOPMOD Block 2 upgrade.

Other equipment provided on the British test guns are the tan Ergo Grip pistol grip, tan Tangodown rail protectors and KAC’s new micro backup iron sight (Model: P/N: 98474 NSN: 1005-01-499-6868) which is adjustable from 2 to 600 meters.  This is significantly lower in profile than KAC’s original design.  The front sight is folding and also manufactured by KAC (Model: P/N: 99051 NSN: 1005-01-473-1410).

The optic chosen by the British MOD is an ACOG manufactured by Trijicon.  It is a 6×48 mm, which is powered by both fiber optic and tritium lamp.  The body of the ACOG is manufactured from 7075 T6 aircraft aluminum, the same as the receivers of the rifle.  The fiber optic lights the reticle during daylight hours and the tritium lamp in low to no light.  The fiber optic is adjustable to determine how bright the shooter wants the chevron to be.  The optic has a built-in bullet drop compensator for the 7.62mm round.  Each adjustment is 1 click per ¼-inch at 100 yards.  The bullet drop compensator adjusts for drop of the 7.62x51mm ball round from 100 to 1,200 meters.  On top of the optic is a Mil-Std 1913 rail which has attached to it a Trijicon LED RMR or Rugged Miniature Reflex sight.

When the dust settled and the results were in, the new British L129A1 rifle was to be manufactured by Lewis Machine and Tool.  Lewis beat out the most prolific manufacturers in the business with his MRP and as of this writing the deliveries continue.

At the same time the LM308MWS was getting ready to hit the commercial market.  The configuration of the first rifles to leave LMT were the same as that of the L129A1 with the main differences being black instead of tan furniture and using the LMT back-up sights.  Lewis does not believe in a final production gun.  LMT’s research and development teams are always looking to improve the performance of their weapons.  Over the last couple years due to other research and testing of new products and simply learning more about the dynamics of the monster, LMT has implemented several upgrades and enhancements.

In the intervening two years some of the changes made are as follows: The bolt carrier has had 4 major modifications.  First is the underside of the front of the carrier.  Two flares are cut in the base.  This allows easier insertion of a fully loaded magazine by allowing the rounds to sit higher into the carrier rather than pushing them straight down making it difficult to insert a fully loaded magazine on a closed bolt.  The second is the location of the main gas exhaust port has been moved further forward on the carrier.  Research showed that when the weapon cycled with the original placement of the port, gas would be vented into the receiver.  By moving the port forward a significant amount of gas is bled out before the port moves into the receiver.  The third is modification to the face of the bolt carrier.  The same support rib found on the LMT Enhanced Carrier is found now on the 7.62 bolt carrier. This supports the entire diameter of the cartridge.  The last major change has been the finish.  The original finish used was chrome.  LMT experimented with a nickel type finish (proprietary) that had excellent results and began plating carriers.  It was a nickel type finish. Sometime after it went into production LMT engineers felt it was not giving them all the advantages they expected and decided to go back to the chrome plating.

The inside of the Lewis Machine & Tool plant in Milan, Illinois. (Courtesy of LMT)

The bolt went through some changes as well.  First the mass was increased right behind the locking lugs right up to the point of where the bolt fits into the rib on the new carrier increasing strength.  Probably the most interesting and notable of all changes was the addition of a second ejector.  Through work on another program LMT engineers found that a second ejector improves ejection reliability in faster cycling weapons.  Certainly with the 16-inch barrel it would be an improvement.  Lewis has always tended to take little steps to increase reliability to insure his customers would have the best possible working weapon.  This is another example.  Those of you who save your brass, well you will have to walk a little farther to pick them up now.

Based on Lewis’ track record one can imagine further improvements are coming down the pike.  All of his weapon systems are works in progress.  You can always improve as no system is perfect.

The LM308MWS, the All Purpose Rifle
Since the introduction of the weapon, Lewis has released additional calibers to his platform to allow his rifle to be used for hunting different game as well as competition.  That is 6 different calibers to be exact.  All that is required to change to these calibers is to install a barrel assembly as the exact same magazine and bolt are used.  The LM308MWS can be now chambered in 7.62x51mm (.308 Win), 243 Win, 260 Rem, 7mm-08, 6.5 Creedmoor and .338 Federal.

The .308 Win cartridge is one of the most versatile calibers in the industry.  Millions of government dollars have been spent on the development of this cartridge for both ball and match loads.  There is no game in North America that cannot be taken with this caliber and it is the choice cartridge in law enforcement and military sniping.  There are endless manufacturers of this ammunition in any configuration imaginable. Bullet weights go from 110 to 190 grains.

The .243 Win cartridge is a light recoil, highly popular versatile cartridge.  With its lighter (75 to 85 grain) loads it is an excellent varmint cartridge from woodchuck right up to coyote.  The largest game one would reasonably want to attempt with a .243 Win caliber would be white tail deer and that would be with a heavier 90 to 115 grain.  This versatile round is quite commonly available and is undoubtedly one of the most popular cartridges in the United States if not all over the world.  This ammunition is made by nearly every large munitions manufacturing plant for commercial ammunition.

The LM308MWS is the host weapon to this weapon system. The monolithic upper receiver accepts removable barrels permitting the weapon to be multi use.

The .260 Rem round is an excellent small deer cartridge.  Loaded with lighter projectiles it makes an excellent varmint rifle.  Low recoil makes it appeal to younger hunters and when you put it in an autoloading firearm like the MRP recoil is decreased even more.  The main problem with this cartridge is availability.  It is known for excellent long range accuracy and will kill effectively any animal in the deer category.  Many people who shoot this cartridge are reloaders and custom load to whatever they are hunting.  This cartridge has been used in precision competition around the world. The most common factory loads for this caliber are 120 and 140 grain. If you are a reloader you have much more options for bullet weights and they will range from 90 to 160 grains.

The 7mm-08 is another light recoil cartridge that is ample for taking larger game up to moose.  Shot placement is critical going directly for the heart and lungs.  It would be questionable how the bullet may perform going through shoulder bones and such.  Its true place may best be with deer and elk.  It is much more common than the .260 Rem cartridge as far as finding ammunition and options of bullet types.  Most common factory loads area 140 and 150 grains.  This versatile cartridge is used for varmint, small to medium game, silhouette and long range shooting.

Introduced in the spring of 2006, the .338 Federal is an excellent cartridge giving more power than the standard .308 Win round.  Taking a .308 Win cartridge case, it is necked to accept a .338 caliber projectile.  Bullet weights normally run from 180 to 210 grains.  This cartridge drives a 210 grain projectile at 2,630 feet per second with 3,226 foot pounds of energy.  The main purpose of this cartridge was to give big game hunters a larger diameter bullet for more weight and overall energy on target without the magnum recoil.  This devastating cartridge is well suitable for dear, bear and elk.  The shooter of this cartridge has a good selection of loads from Federal based on what they are hunting.  Although there is significantly more recoil than a .308 Win, being shot in an autoloader such as the MRP makes this a very comfortable round to shoot. Numbers show this round to have equal or better energy than the 7mm Mag cartridge.

The 6.5 Creedmoor was developed from the ground up to be a true match cartridge.  The original intent was to develop a round that a precision shooter would be able to take factory ammunition and win competitions of the highest levels.  Of course it has made its way into the hunting world as well.  The projectile weight runs from 120 to 140 grains.  This cartridge is well suited for small to medium size game.  Large deer and rams are no problem for this flat shooting precision cartridge.

The same MRP upper receiver was used for the entire evaluation.  All of the barrels were direct gas barrels chambered in .308 Win, .338 Federal, .243 Win, .260 Rem, 7mm-08 and 6.5 Creedmoor.  The same toque wrench was used and each barrel screw was torqued to the specified 140 inch pounds.  The same bolt carrier group and magazine were used to fire the variety of cartridges.  The same optic, a Leupold Mark 4 3.5 to 10x scope with an illuminated reticle, was used for all testing and was never removed from the MRP.  This scope has a 40mm objective and is equipped with bullet drop compensator for the 7.62x51mm round with a 168gr projectile.  The illuminated reticle is turned on or off by the user and has 11 increments of brightness.  Every group was shot at 100 yards off of a bench.

All six types of ammunition were fired and every group fell under 1 MOA.  (There was an occasional flyer due to operator fatigue firing all those rounds.)  The LM308MWS maintained precision accuracy with each barrel being removed and torqued.  There were no malfunctions of any kind with any caliber ammunition and the weapon was not cleaned during the testing.  This rifle is truly modular; you are able to hunt everything from varmint right up to elk and black bear by removing two screws and snapping in a new barrel.  For the professional, this rifle can be used as a duty/military sniper rifle as well as the competitive shooter.  LMT continues to not only offer more calibers but also continues to make the best even better because failure is not an option.

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