The LMT MRGG-A Reference Rifle is the semi-automatic version of the Mk 24, the 6.5 Creedmoor rifle LMT Defense builds for U.S. Special Operations Command (SOCOM): long-range reach from a carbine-length barrel. It pairs a 14.5-inch stainless barrel with LMT's monolithic upper and fully ambidextrous MARS-H lower, and it leaves the factory as a short-barreled rifle (SBR). This is a National Firearms Act (NFA) item.
SOCOM has said the 6.5 Creedmoor cartridge can roughly double a shooter's chance of a hit out to 1,000 meters. For context, the 5.56mm M4A1 is commonly credited with about 500 meters of effective range and the 7.62mm M110 about 800. High-ballistic-coefficient 6.5mm bullets hold velocity and resist wind better than comparable .308 match loads, and they do so from a barrel short enough for vehicle and building work.
SOCOM's Mid-Range Gas Gun (MRGG) effort began in the late 2010s and split into two lanes: a 20-inch sniper rifle (MRGG-S, awarded to Geissele) and a 14.5-inch assaulter's rifle (MRGG-A, awarded to LMT). LMT's contract, announced in August 2025, carries a $92 million ceiling and runs through 2035.
SOCOM has since given LMT's rifle its own designation: the Mk 24. It is in production and is planned to replace the Mk 17 SCAR-H, with fielding expected to begin in fiscal year 2026. MRGG-A is the program; Mk 24 is the rifle.
A reference rifle is not a look-alike. LMT builds it to the program configuration, with semi-automatic fire control in place of the issued rifle's select-fire:
One rigid rail, mirrored controls, a barrel you can change at the bench. This is the program rifle, not a costume.
Compared with a 20-inch rifle, you give up roughly 150 feet per second with 140-grain match ammunition. In return you get a rifle that handles like a carbine, stows in a truck, and carries a suppressor without turning into a pole. Mid-length gas softens the impulse and slows the carrier, which helps reliability on a short rifle. And because it leaves LMT as a factory SBR, it stays a true 14.5 inches, with no pinned-and-welded device stretching it to 16. Its 1:8 twist stabilizes the 140- to 147-grain match bullets that make 6.5 Creedmoor what it is.
This rifle earns its place with three buyers: the collector who wants the nearest thing to the issued SOCOM rifle; the practical or DMR shooter who wants realistic work to 800 yards in a compact package; and the MARS-H owner standardizing on one platform. If you would prefer a rifle that isn't an SBR, a 20-inch MRGG-S-pattern rifle may be the better fit, and we will gladly help you choose one.
Plenty of rifles borrow a military look. This one earned it. Pair it with a scope like the Nightforce ATACR 1-8x24 LMT has shown on it, and you have one rifle that covers the room and the ridgeline. Questions on optics or setup? Call us. Long range, DMR, 6.5 Creedmoor: we speak your language.
| Manufacturer | LMT Defense (Lewis Machine & Tool) |
| Model | MRGG-A Reference Rifle |
| Military designation | Mk 24 (issued select-fire rifle, U.S. Special Operations Command) |
| Manufacturer part number | MLK65145L-MARS-SR |
| UPC | 815415016931 |
| Type | Factory short-barreled rifle; NFA item |
| Caliber | 6.5 Creedmoor |
| Action | Semi-automatic, direct impingement |
| Gas system | Mid-length, LMT gas block, straight gas tube |
| Barrel | 14.5" stainless steel, 1:8 twist |
| Muzzle device | A2 birdcage flash hider |
| Upper receiver | Monolithic, 7075-T6 billet, continuous Picatinny top rail, M-LOK, forward assist |
| Lower receiver | MARS-H, fully ambidextrous, flared magwell |
| Bolt and carrier | Dual-ejector bolt; full-auto-profile carrier with forward-assist serrations |
| Barrel retention | Dual cross-bolt, user-changeable (LMT MWS compatible) |
| Trigger | LMT AXLE two-stage |
| Buffer | H3 |
| Charging handle | Ambidextrous |
| Stock and grip | Magpul DT stock and Magpul K2 grip, in flat dark earth |
| Capacity | 20 rounds; one magazine included |
| Finish | Black |
| Included | One magazine, owner's manual |
| Sights | Not included |
| Optic and mount | Not included |
| Suppressor | Not included |
| Condition | Factory new |
| Ships | 3 to 7 days when in stock; 3 to 8 weeks when ordered from the manufacturer |
What is the LMT MRGG-A?
The rifle LMT Defense supplies to U.S. Special Operations Command under the Mid-Range Gas Gun - Assault program. SOCOM designates the issued rifle the Mk 24. The reference rifle is its semi-automatic commercial counterpart.
Is the Mk 24 the same rifle as the MRGG-A?
Yes. MRGG-A (Mid-Range Gas Gun - Assault) is the SOCOM program, and Mk 24 is the designation SOCOM gave the rifle LMT builds under it. It should not be confused with the Navy's Mk 24 Mod 0, which is a Heckler & Koch pistol.
What is the difference between MRGG-A and MRGG-S?
MRGG-A is the 14.5-inch assaulter's rifle, built by LMT. MRGG-S is the 20-inch sniper-support rifle, built by Geissele and designated the Mk 1 Mod 0.
Is the MRGG-A Reference Rifle full-auto?
No. The contract rifle is select-fire; the commercial reference rifle is semi-automatic. It uses a full-auto-profile carrier for its mass and durability.
How does it ship?
As a factory SBR, it ships to your NFA dealer with one magazine and the owner's manual.
Will MWS .308 barrels fit?
LMT states the upper accepts most MWS .308 and 6.5 Creedmoor barrels through its dual cross-bolt system.
THIS IS A SERIALIZED FIREARM. It must ship to a Federal Firearms License holder. No civilian exceptions.
Buying and shipping through Charlie’s is easy, but there is some information you need to know. Only a federally licensed firearms dealer may receive a firearm or federally regulated serialized item (like a receiver or suppressor). We cannot ship these items directly to you. Please follow these steps to process your transaction:
1) Check your state laws to make sure the federally regulated item you want to purchase is legal in your state. Your FFL dealer should be able to give you all of the necessary information regarding your state specific laws. But, if we ship to your FFL, and there is a legal issue, we cannot accept a return. So please make sure that you know and follow your local and state laws.
2) A quick google search will show you what Federal Firearms Licensed (FFL) dealers are in your area. When you are ready to purchase, contact the FFL dealer you would like to use and get their shipping address. During the check-out, put YOUR address in the “billing” section and the FFL DEALER’S address in the “shipping” section. If you don’t know your FFLs address, that’s okay. You can send the information later.
3) After check out, make sure to contact your FFL dealer to ensure they will receive your shipment for you (most do this for a small fee, but you should always double check).
4) Have your dealer send us a copy of their FFL to FFL@CharliesCustomClones.com. Charlie’s does not reach to your FFL (MAKE THEM EARN THEIR FEE!!!)
5) Be patient! In order to ensure we remain compliant with all federal laws, our compliance department is kept separate from our sales and operations team. Please allow a few days for our compliance officer to verify all of your dealer’s documents and ensure all federal laws are being observed. You should hear from our compliance department within 3-4 business days. If not, feel free to reach out for a status update.
That’s it! We try to make this process as simple as possible for our customers, but if you are unfamiliar the process or have any other questions, please visit our How to Buy a Firearm page for more details.
California and New York residents please, click here. The process may be different due to state specific laws.
NOTE: The free shipping option does not apply to full rifles, unless purchased with a riflescope. If you choose free shipping at check-out, we will bill you for shipping later.
LMT Defense
LMT Defense
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