Mid-Range Gas Gun

Selection and contract

SOCOM's objective statement for the MRGG-S called for a sniper support rifle with a threshold accuracy requirement of 1.0 minute of angle at 100 yards and an objective requirement of 0.5 minute of angle at 100 yards. The command sought a semi-automatic rifle with a 20-inch barrel, a weight under 10.5 lb (4.8 kg), full-time suppressed fire, and a user-swappable barrel for 7.62x51mm NATO.^[2][6]

LMT submitted a rifle derived from its Modular Ambidextrous Rifle System-Heavy (MARS-H). The company said it delivered rifles for SOCOM down-select trials in 2022 and reported average accuracy just under 0.85 minute of angle for its initial program delivery.^[7]

On 31 August 2023, Geissele founder Bill Geissele announced that the company's submission had been selected for the MRGG-S. Geissele stated that the rifle had been known internally as "Project Joy" and that SOCOM's designation for the weapon was Mk 1 Mod 0.^[2][8] USSOCOM awarded Geissele Automatics of North Wales, Pennsylvania, an indefinite delivery/indefinite quantity contract, H92403-23-D-0003, with a ten-year ordering period and a maximum ceiling of US$29,263,029. The contract was for a sniper support weapon and designated marksman rifle, including spare parts, vendor support, new equipment training, engineering, and travel. It was awarded as a follow-on production contract from a competitive prototype agreement under 10 U.S.C. § 4022(f), with USSOCOM at MacDill Air Force Base, Florida, as the contracting activity.^[6]

Design

The Mk 1 Mod 0 is a gas-operated AR-10-pattern semi-automatic rifle. It uses billet aluminum upper and lower receivers, ambidextrous controls, a 20-inch cold-hammer-forged chrome-lined barrel, a free-floating M-LOK handguard, and a Geissele Super Semi-Automatic Enhanced two-stage trigger.^[9][10] The rifle is chambered in 6.5mm Creedmoor and has a user-swappable barrel for 7.62x51mm NATO. Its factory configuration pairs the rifle with Geissele's "Super Night Owl" titanium suppressor. Geissele has stated that the MRGG-S grew out of its Very Long-Range Semi-Automatic Sniper System work.^[9][10]

Selection and contract

The MRGG-A is the shorter, assaulter-oriented requirement within the MRGG program. It uses a 14.5-inch barrel, has selective-fire capability, and uses a different stock than the MRGG-S. SOCOM continued the assaulter requirement after the MRGG-S award.^[6][4]

The U.S. Department of Defense announced LMT's MRGG-A award in its daily contracting notice on 22 August 2025. The contract covered "medium range gas gun-assault kits, spare parts and accessories, new equipment training, and engineering change proposals." It had a maximum ceiling of US$92 million and an ordering period running through 14 August 2035.^[11][1]

Design and fielding

LMT's MRGG-A is based on the MARS-H family, an AR-10-style rifle platform. The MRGG-A configuration has a 14.5-inch barrel, a monolithic Picatinny rail on the upper receiver, M-LOK accessory attachment points on the handguard, ambidextrous controls, and fully automatic fire capability.^[1] The Mk 24 MRGG-A can be configured for 7.62x51mm NATO or 6.5mm Creedmoor through a quick-change barrel system. In May 2026, SOCOM's program manager for Special Operations Forces Lethality said that the command had begun procuring the assaulter variant but had not yet fielded it.^[4] Later that month, a SOCOM spokesperson told Task & Purpose that the Mk 24 was in production, would replace the Mk 17 SCAR-H, and was expected to begin fielding during fiscal year 2026.^[3]