Military Factory logo

United States Navy Mark 12 Special Purpose Rifle (Mk 12 SPR) Sniper Rifle / Designated Marksman Rifle (DMR)

The Mk 12 SPR has been used with deadly efficiency in both Afghanistan and Iraq theaters or war.

 Updated: 7/31/2017; Authored By Staff Writer; Content ¬©

The Mark 12 Special Purpose Rifle (Mk 12 SPR) entered service with the United States Special Forces in 2002 and has seen continuous use since then. The weapon has been featured prominently in operations throughout the Afghanistan and Iraq theaters of war often times in the hands of the highly-trained specialists of the US Army and US Navy. A prime operator of the SPR is, in fact, the US Navy SEALs which dictates that the SPR be a reliable, extremely effective and robust weapon system. The Mk 12 was specifically developed for specialized use by the Naval Surface Warfare Center Crane Division (NSA Crane) and is based highly on the AR-15/M16 pattern with a few noticeable external additions and modifications.

The Mk 12 was born out of a joint US Army/Navy requirement for a compact, semi-automatic capable sniper rifle system. Multiple prototypes were drawn up and these were then heavily tested resulting in the finalized "Mk 12" form. Like the AR-15 and M16 before it, the Mk 12 was chambered for a specially-developed version of the 5.56x45mm NATO cartridge firing from a semi-automatic, gas-operated rotating bolt action. The weapon feeds from a 20- or 30-round detachable box magazine and retains much of the AR-15/M16 form and functionality. Effective range is listed out to 600 yards with a muzzle velocity reported at 3,050 feet per second. The pistol grip is ergonomically grooved for a firm hand hold while the trigger is set within an integrated guard. The magazine feeds just ahead of the trigger in typical M16-style fashion. The forend is covered over in a perforated, tubular handguard to which a rail system is affixed along the front bottom face - this allows use of a collapsible bipod for steady firing. The upper portion of the receiver and the forend also sport a rail system for the use of accessories and optics as needed. The shoulder stock extends from a collapsible tubular frame and helps the operator achieve a four-point firing platform (when using both hands, a bipod and the shoulder stock) for maximum accuracy at distance. The barrel protrudes only a short distance from the forend and is capped by a single-baffled muzzle brake. The barrel measures in at 18 inches in length while overall length of the SPR is 37.5 inches. A fully-loaded system weighs only 10lbs, slightly more than the original M16. In comparison, the M16 measures in at 39.5 inches long with a 20-inch barrel length.

It should be noted that there are several iterations of the Mk 12 system currently in circulation and this is expected when detailing special forces weaponry. To date there are two distinct identified forms known as the "Mk 12 Mod 0" and the "Mk 12 Mod 1". The formal "long designaton" designation for the rifle system is "United States Navy Mark 12 Mod0/1 Special Purpose Rifle".

Images Gallery


United States Navy Mark 12 Special Purpose Rifle (Mk 12 SPR) Technical Specifications

Service Year: 2002
Type: Sniper Rifle / Designated Marksman Rifle (DMR)
National Origin: United States
Manufacturer(s): ArmaLite; Colt; Knights Armament Company - USA / Diemaco - Canada

Design (Internal, Dimensions and Weights)

Firing Action: Gas-Operated, Rotating Bolt
Available Caliber(s): 5.56x45mm NATO
Ammunition Count / Feed: 20- or 30-round detachable box magazine
Overall Length: 952 mm (37.48 inches)
Barrel Length: 457 mm (17.99 inches)
Weight (Empty): 9.92 lb (4.50 kg)
Sighting Assist: Adjustable Iron; Optional Optics


Muzzle Velocity: 3,050 feet/sec (930 m/sec)
Typical Range: 1,800 feet (549 meters; 600 yards)

Global Operators / Customers

United States

Model Variants (Including Prototypes)

Mk 12 SPR - Base Series Designation
Mk 12 Mod 0 - Used by the US Navy SEALs
Mk 12 Mod 1 - Used by the US Army Rangers