Mk 12 Special Purpose Rifle
Naval Surface Warfare Center Crane · Sniper Rifle · In Service · 2002
Also known as: Mk 12 SPR, SPR, Special Purpose Rifle, Mk 12 Mod 0, Mk 12 Mod 1
Overview
The Mk 12 Special Purpose Rifle is a designated marksman variant of the M16/AR-15 platform, developed by the Naval Surface Warfare Center Crane Division for US Navy SEALs and Army Special Forces. Chambered in 5.56x45mm NATO with an 18-inch match-grade stainless steel barrel, the Mk 12 extends the effective range of the standard M16 to approximately 600 meters while maintaining the familiar AR-15 manual of arms. The rifle was designed to fill the gap between the standard infantry rifle and the 7.62mm M24 sniper system, providing squad-level precision fire capability.
Specifications
| Weight (empty) | 4200 g (148.2 oz) |
| Weight (loaded) | 4700 g (165.8 oz) |
| Overall Length | 965 mm (37.99") |
| Barrel Length | 457 mm (17.99") |
| Action Type | Gas Operated Direct Impingement |
| Firing Mechanism | Rotating Bolt |
| Trigger Type | Two Stage |
| Trigger Pull | 20 N (4.5 lbf) |
| Magazine Capacity | 20 rounds |
| Magazine Type | Detachable Box |
| Muzzle Velocity | 854 m/s (2802 fps) |
| Muzzle Energy | 1459 J (1076 ft·lbf) |
| Effective Range | 600 m (656 yd) |
| Maximum Range | 1800 m (1968 yd) |
| Barrel Rifling | Right Hand |
| Rifling Twist | 178 mm (7.01") |
| Number of Grooves | 6 |
| Frame Material | Aluminum Alloy |
| Barrel Material | Stainless Steel |
| Stock Material | Polymer Collapsible |
| Finish | Matte Black |
Calibers
- 5.56x45mm NATO · primary · 5.56x45mm NATO — also known as .223 Remington, 5.56mm NATO, 5.56x45mm
Features
- Firing modes: Semi Automatic
- Feed systems: Detachable Box Magazine
- Safety mechanisms: Manual Safety, Firing Pin Safety
- Features: Free Floating Barrel, Match Grade Barrel, Suppressor Ready, Picatinny Rail, Bipod Mount, Harris Bipod, Ops Inc Suppressor, Leupold Scope
Variants
- Mk 12 Mod 0 — Original
- Mk 12 Mod 1 — Improved
- Mk 12 Mod H — Holland Variant
Service history
Operators
- United States Navy SEALs · adopted 2002 · as Mk 12 SPR
- United States Army Special Forces · adopted 2002 · as Mk 12 SPR
- United States Marine Corps · adopted 2005 · as SAM-R
- United States Army Rangers · adopted 2003 · as Mk 12
Conflicts
- War in Afghanistan (2001-2021)
- Iraq War (2003-2011)
- War on Terror (2001-present)
Production
Production years: 2002-present
Built in limited numbers primarily for SOCOM and select conventional units. Exact production figures classified.
Origin
Country of origin: United States
Notes
The Mk 12 exists in two main configurations: Mod 0 with a Douglas barrel and PRI Gen III handguard, and Mod 1 with a KAC match barrel and free-float RAS handguard. Both configurations use the Leupold Mk 4 2.5-8x36mm scope as standard optic. The rifle is typically fielded with an OPS Inc. 12th model sound suppressor. The 1:7 inch twist rate is optimized for firing the heavier 77-grain Mk 262 Mod 1 open-tip match ammunition developed specifically for this platform.
Background
The Mk 12 SPR proved so effective in Iraq and Afghanistan that it influenced the development of the entire designated marksman rifle concept across NATO militaries. Navy SEALs paired it with the purpose-developed Mk 262 Mod 1 77-grain ammunition, which pushed the 5.56mm cartridge to its maximum effective potential and demonstrated that the intermediate caliber could be lethal well beyond its traditionally accepted range.