Centurion Arms MK12 Mod 0 Complete 5.56 NATO Rifle 18" Barrel - 30 Rd

Centurion Arms MK12 Mod 0 Complete 5.56 NATO Rifle 18" Barrel - 30 Rd

The Centurion Arms MK12 Mod 0 was built to reach out and deliver — with the kind of first-round precision that only a purpose-engineered designated marksman platform can provide. Rooted in the combat-proven legacy of the United States Navy Mark 12 Special Purpose Rifle, this faithful reproduction captures every defining characteristic of the original Mod 0 configuration: the 18" match-grade stainless barrel, the free-floating PRI Gen III handguard, the OPS Inc. brake and collar, and the Centurion Arms Advanced Sniper Trigger — all wrapped in forged mil-spec receivers built to the same standards that armed Naval Special Warfare operators downrange.

The MK12 SPR concept was born from a simple but powerful idea: give a special operator the extended reach and precision of a designated marksman rifle without abandoning the familiar controls and ergonomics of the AR platform. Developed by the Naval Surface Warfare Center, Crane Division, the MK12 filled the critical gap between a standard M4 carbine and a dedicated sniper system — and it did so with remarkable effectiveness. The 18" free-floating barrel, tuned for the 77-grain Mk 262 OTM cartridge, unlocked engagement distances far beyond what standard M855 ball ammunition and shorter barrels could reliably achieve.

The Centurion Arms MK12 Mod 0 doesn't just honor that legacy — it delivers it, component by component, with the uncompromising build quality the Centurion Arms name demands. Whether you're a collector chasing historical authenticity, a precision shooter demanding a purpose-built DM platform, or an operator who knows exactly what this rifle represents — the M12 Mod 0 is ready.

18" Match-Grade Stainless Steel Barrel
Air-gauged for dimensional consistency and Cerakoted Black for corrosion resistance, this 1:7" right-hand twist barrel is purpose-built for 77-grain OTM ammunition — delivering the long-range accuracy and terminal performance the original MK12 SPR program was designed around.

Free-Floating PRI Gen III Handguard with SPR Straight Top Rail
The free-float design eliminates all contact with the barrel, removing the vibration and pressure that rob precision rifles of consistency. The integrated PRI SPR Straight Top Rail delivers a seamless, uninterrupted optic mounting surface in faithful Mod 0 configuration.

Mod 0-Correct Iron Sight Package
PRI flip-up front sight — mounted in place of the standard gas block as per original Mod 0 spec — paired with the ARMS, Inc. #40 flip-up rear sight for an authentic, battle-ready iron sight solution straight from the factory.

OPS Inc. Muzzle Brake and Collar
Replicating the original SPR muzzle configuration, the OPS Inc. brake tames recoil and muzzle rise while the precision collar provides correct alignment for the OPS Inc. 12th Model Suppressor — making this rifle suppressor-ready from day one.

Chrome Sandcutter BCG with E4 Tapered Lug Bolt
The enhanced tapered lug geometry and chrome lining deliver superior lockup, long-term durability, and smooth, reliable cycling — even under sustained or suppressed fire conditions.

M84 Gas Buster® Charging Handle:
Designed to redirect propellant gases away from the shooter's face during suppressed operation, with an oversized latch for positive manipulation in any condition, including gloved hands.

Centurion Arms AST Two-Stage Trigger
The Advanced Sniper Trigger delivers a smooth, defined first stage and a crisp, repeatable break — giving precision shooters the shot control needed to maximize the MK12 platform's inherent accuracy at distance.

Mid-Length Gas System with Low-Profile Pinned Gas Block: Tuned to the 18" barrel for optimal dwell time, reduced felt recoil, and reliable cycling across a wide range of 5.56 NATO loads — including heavier 77-grain OTM projectiles.

Forged Mil-Spec CM4 Upper and Lower Receivers
Both receivers are forged to mil-spec standards with Type 3 hard coat anodizing and M4 extended feed ramps for enhanced feeding reliability and proven long-term durability.

Specifications

• Caliber: 5.56×45mm NATO
• Barrel Length: 18"
• Barrel Material: Match-Grade Stainless Steel, Air-Gauged
• Barrel Finish: Cerakote Black
• Twist Rate: 1:7" Right-Hand
• Gas System: Mid-Length
• Gas Block: Low-Profile Pinned
• Muzzle Device: OPS Inc. Muzzle Brake and Collar
• Suppressor Interface: Compatible with OPS Inc. 12th Model SPR MBS
• Upper Receiver: Forged Mil-Spec CM4, Type 3 Hard Coat Anodized, M4 Extended Feed Ramps
• Lower Receiver: Centurion Arms CM4 Forged
• Bolt Carrier Group: Centurion Arms Chrome Sandcutter BCG, E4 Tapered Lug Bolt
• Charging Handle: M84 Gas Buster®, Military Big Latch
• Trigger: Centurion Arms AST Two-Stage Advanced Sniper Trigger
• Trigger Guard: Aluminum Winter Trigger Guard
• Grip: Ergo Black
• Stock: A2 Fixed
• Buffer: Rifle Length
• Front Sight: PRI Flip-Up (Mod 0 Gas Block Position)
• Rear Sight: ARMS, Inc. #40 Flip-Up
• Handguard: PRI Gen III Free-Float with SPR Straight Top Rail
• Optics: Not Included
• Weight: Approx. 6.9 lbs
• Overall Length: Approx. 32.5 Inches
• Included in Box: Rifle, (1) 30-Round Magazine (where state law permits), Digital USGI Manual, Centurion Arms Propaganda