Centurion Arms MK12 Mod 1 — 18" 5.56 NATO Rifle

The Centurion Arms MK12 Mod 1 is an 18" AR‑pattern rifle chambered in 5.56 NATO, built to echo the form and function of the MK12 Special Purpose Rifle (Mod 1) concept. The rifle combines an 18" match stainless barrel with a free‑float C4 handguard, a pinned low‑profile MK12 gas block, and a two‑stage AST trigger to provide a stable, precision‑oriented platform for designated marksman and precision‑focused roles.

Key features

• Centurion low‑profile pinned MK12 gas block for secure alignment and reliability
• 12" Centurion C4 free‑float M‑LOK handguard for modular accessory mounting
• Centurion Sandcutter chrome BCG with E4 tapered lug bolt
• M84 Gas Buster® charging handle (large latch) for positive manipulation
• Centurion AST two‑stage trigger for controlled, consistent breaks
• Forged mil‑spec upper and lower receivers with M4 extended feed ramps
• OPS Inc. brake and collar compatible with suppressor interfaces (as configured)

Technical specifications

• Barrel: 18" stainless match, air‑gauged, 1:7" RH twist, Cerakote finish
• Handguard: 12" Centurion C4 free‑float M‑LOK rail
• Gas system: Mid‑length with low‑profile pinned MK12 gas block
• Trigger: Centurion AST two‑stage trigger
• Upper/Lower: Forged CM4 receivers, M4 extended feed ramps
• Controls & furniture: Aluminum winter trigger guard, Ergo grip, B5/SOPMOD‑style stock