LMT Mars-H Lower

The LMT MARS-H Lower (Modular Ambidextrous Rifle System - Heavy) is one of the most advanced AR-10/7.62 NATO lower receivers available today. Manufactured by Lewis Machine & Tool (LMT), this lower receiver is designed for battlefield reliability, modularity, and ergonomic efficiency, making it a top choice for military forces, law enforcement, and civilian shooters who demand precision and durability in their firearms.

As a fully ambidextrous lower receiver, the MARS-H Lower offers enhanced control, allowing users to manipulate the rifle’s functions seamlessly, regardless of their dominant hand. The robust forged aluminum construction, integrated QD sling points, and flared magazine well make it a high-performance choice for those seeking the best in modern battle rifle technology. The SR-25 piqued the interest of the US Special Operations Command because of its large magazine capacity and quicker engagement time than bolt-action rifles. In May 2000, SOCOM adopted the SR-25 as the Mk 11 MOD 0 after some modifications. Among the modifications were a quick detachable sound suppressor attachment and a shortened 20 in (510 mm) barrel that could fire M118 and M118LR 7.62×51mm NATO bullets. Accessories could be mounted thanks to an 11.35 in (288 mm) free-floating handguard rail system. In addition to an M16A2 stock and pistol grip, flip-up front sights and adjustable back-up iron sights were incorporated. The SSR Mk 20, the sniper version of the FN SCAR, replaced the Mk 11 MOD 0 in SOCOM's inventory starting in the middle of 2011. By 2017, the Mk 11 had been fully replaced.

LMT has been at the forefront of innovative firearm design since its founding in 1980. Known for supplying the U.S. military, British Armed Forces, and elite tactical units worldwide, LMT has earned a reputation for producing battle-proven weapons and components. The MARS-H system builds upon this legacy, taking the traditional AR-10 lower receiver platform and refining it with modern enhancements that improve functionality and reliability in combat and tactical environments.In order to accommodate various scope mounts or a carrying handle with iron sights (front sight mounted on the rail located on the forward end of the non-modular handguard), the SR-25 enhanced match rifle uses the more recent URX II Picatinny-Weaver rail system on the top of the receiver instead of the older Mk 11 free-floating RAS. At 100 yards (91 meters), the match version is intended to shoot with a precision of 0.5 minutes of angle, or 0.5-inch (13 mm) groupings.

The Mk 11 MOD 0 system is made to fire match-grade ammunition and is chambered for 7.62×51mm NATO.    The MARS-H Lower is a key component of LMT’s full MARS-H rifle system, which is designed to provide modularity and compatibility with various upper receivers. Whether chambered in 7.62 NATO, 6.5 Creedmoor, or .260 Remington, the LMT MARS-H Lower ensures seamless compatibility, allowing users to adapt their firearm for long-range precision shooting, military operations, or law enforcement engagements.

 

One of the most outstanding features of the LMT MARS-H Lower is its fully ambidextrous control layout. Unlike many traditional AR-style rifles, which are optimized for right-handed users, the MARS-H provides mirror-image controls on both sides of the receiver. This ergonomic design makes the MARS-H Lower particularly useful for tactical shooters, military operators, and law enforcement officers who may need to switch hands in cover-based shooting situations. The ambidextrous functionality is not just a convenience—it is a critical feature that enhances combat effectiveness and situational adaptability.

LMT has built the MARS-H Lower to withstand the harshest battlefield conditions. The receiver is CNC machined from 7075-T6 aluminum, a high-strength aerospace-grade material known for its lightweight durability. The hardcoat anodized finish provides corrosion resistance and added surface hardness, ensuring the receiver can endure rugged field conditions, extreme temperatures, and prolonged use.

The flared magazine well is another standout feature, designed to facilitate rapid magazine changes while also reinforcing the lower receiver’s structural integrity. This feature is particularly useful in high-stress environments, where reloading speed can be a decisive factor in engagements.

Additionally, the integrated QD sling attachment points on the rear of the receiver offer shooters the ability to quickly attach and detach slings for stability and maneuverability, further enhancing the rifle’s modular capabilities. The LMT MARS-H Lower is compatible with standard AR-10 triggers, allowing users to customize their trigger setup based on their specific shooting preferences. Whether opting for a precision two-stage trigger for long-range accuracy or a combat-ready single-stage trigger for rapid engagements, the MARS-H provides versatility without compromising reliability.

LMT’s own two-stage trigger option offers a crisp and clean break, making it an excellent choice for shooters looking to maximize accuracy in precision shooting applications. The design of the trigger guard is enlarged, ensuring that the rifle remains fully functional even when wearing gloves in cold or tactical environments.

Because of its architecture, the MARS-H Lower is compatible with LMT's MRP (Monolithic Rail Platform) upper receivers. Shooters may easily switch out barrels and calibers using this system, which makes it a very flexible and modular firearm system. Depending on mission needs, users can switch between 7.62 NATO for battle rifle applications, 6.5 Creedmoor for accurate long-range shooting, and other calibers thanks to the quick-change barrel system.

This interchangeability is a game-changer for military units, law enforcement agencies, and civilian enthusiasts who demand versatility from a single rifle platform. Instead of owning multiple rifles for different applications, the LMT MARS-H system allows shooters to customize their firearm with different barrels and optics to match their specific needs.

The LMT MARS-H Lower has been adopted by elite military units and special forces around the world. Its combat-proven reliability, ambidextrous controls, and modularity make it an ideal choice for tactical operators and designated marksmen.

Military and law enforcement personnel appreciate its durability and ease of operation, especially when working in dynamic environments where quick reloads, rapid target transitions, and adaptability to different shooting positions are crucial. The semi-automatic functionality provides an excellent balance between precision and firepower, making it effective for mid-range to long-range engagements.

In addition, the LMT MARS-H Lower is designed to integrate with advanced optics, night vision, and thermal imaging systems, ensuring that operators have the best possible sighting solutions in any combat or tactical scenario.

Although the MARS-H Lower was created with law enforcement and military uses in mind, it has also become more and more popular among competitive marksmen, civilian shooters, and gun aficionados. It is a desirable choice for anyone seeking the best AR-10 available because to its ambidextrous controls, robustness, and versatility.Its robust construction, improved ergonomics, and compatibility with top-notch upper receivers for long-range shooting are valued by precision shooters. Because it offers both power and precision over long range, hunters find it extremely helpful for big game hunting, especially when chambered in 6.5 Creedmoor or.308 Winchester.

Additionally, for firearm enthusiasts who value high-quality craftsmanship, the LMT MARS-H Lower represents the pinnacle of AR-10 design, combining battle-tested performance with cutting-edge technology.The LMT MARS-H Lower stands out as one of the most advanced and durable AR-10 lower receivers available today. Its fully ambidextrous controls, battle-proven construction, and seamless compatibility with multiple upper receivers make it a top-tier choice for military, law enforcement, and civilian shooters alike.

For duty rifles, competition rifles, or precise long-range builds, the MARS-H Lower offers unmatched versatility and dependability as a high-performance lower receiver. Its combat-tested design, sturdy yet lightweight construction, and future-proof adaptability guarantee that this lower receiver will always be a strong competitor in the AR-10 platform market. The LMT MARS-H Lower is a wise purchase for anyone looking for the newest in battle rifle technology since it ensures performance, robustness, and versatility in any shooting situation.