The Geissele MRGG-S sniper rifle was officially adopted by USSOCOM in 2023 as the 6.5mm Mark 1 Model 0 sniper rifle (6.5mm Mk.1 Mod.0 rife). The MRGG (Mid-Range Gas Gun) project was started by USSOCOM in 2019, in an attempt to procure more effective replacement weapons for SOF sniper teams and to replace various 7.62x51mm semi-automatic marksman / sniper rifles such as Mk.14 EBR, Knight’s Mk.11 Mod.0 or FN SCAR SSR Mk.20.
Geissele MRGG-S sniper rifle
New project was created around a relatively new but already popular 6.5mm Creedmoor (6.5x49mm) cartridge, which extended the practical range of sniper rifles from 800 to 1200 meters. Use of this cartridge also permits simple change of caliber to a much more widespread 7.62x51mm NATO cartridge and back. Current standard issue SOCOM sniper ammunition in 6.5mm Creedmoor caliber is designated as CARTRIDGE, 6.5MM SPECIAL BALL LONG RANGE, M1200, and is loaded with a 140-grain (9 gram) Berger Hybrid Target bullet. Specified muzzle velocity is 2750 fps, or roughly 840 m/s.
Initial plans were to procure two types of 6.5mm MRGG rifles – MRGG-S (Sniper) and MRGG-A (Assault), the latter being a more compact, select fire weapon for sniper support team members. However, thus far (early 2025) the fate of MRGG-A project remains unclear, while the MRGG-S production contract was awarded in 2023 to the Geissele Automatics company which won a competition against several notable American gun makers such as LaRue, LMT, SIG Sauer and FN America.
Geissele MRGG-S sniper rifle with sound suppressor
The Geissele MRGG-S sniper rifle is built on a classic “AR-10 style” platform. As its name implies, it is a gas operated, semi-automatic precision rifle which uses a Direct Impingement operating system that features the patented Geissele Phased Array gas block with several gas ports. The 20-inch cold hammer forged barrel has a chrome-plated bore and chamber to improve its service life and corrosion resistance. Both upper and lower receivers are made from aluminum alloy and feature fully ambidextrous controls. Trigger is of a match grade, two-stage type. Aluminum alloy forend is free-floating and does not contact the barrel ahead of its nut at the rear. Rifle is equipped with a Magpul PRS Lite shoulder stock and uses Magpul 20-round polymer magazines. No iron sights are fitted by default, but any useful combination of day and night scopes can be fitted to an integrated Picatinny rail. Another “standard issue” accessory for a rifle is a Geissele-made quick-detachable sound suppressor.
Geissele MRGG-S 6.5mm Mk1. Mod.0 sniper rifle basic specifications:
Encyclopedia of firearms and ammunition of the XX and XXI centuries
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