Colt Piston Carbine 18” 5.56 Centurion Mk12 SPR Upper Rifle Knight’s Rail
SOLD FOR: $2,050.00
LSB#: WY250421ML002
Make: Colt
Model: Piston Carbine lower built out to be a MK12 SPR
Serial Number: LP003033
Year of Manufacture: Modern
Caliber: 5.56
Action Type: Semi-Auto, Direct Impingement, detachable magazine fed. This rifle has a California compliant lower that requires the upper and lower be separated before the magazine can be released.
Markings: The left side of the receiver is marked “COLT / PISTON CARBINE TM / CAL. 5.56MM. / LP003033”, “COLT DEFENSE / HARTFORD. CONN. / U.S.A.”, “SAFE FIRE”, The rail is marked “KNIGHT’S ARMAMENT CO. TITUSVILLE, FL WWW.KNIGHTARMCO.COM” , and “SR-15/16 FREE FLOAT RAIL ADAPTER SYSTEM PN 99167”. The barrel and the upper receiver is marked “CENTURION ARMS”. The iron sights are also marked with Knight’s marking.
Barrel Length: 18” medium profile barrel 19.5” with Allen collar and muzzle device for mounting an AEM5 suppressor.
Sights / Optics: The rifle has a 6” picatinny rail for the mounting of optics and accessories. Currently mounted is a set of Knight’s armament back up flip up iron sights
Stock Configuration & Condition: The furniture set on this rifle includes An A2 style butt stock with a 13” length of pull, and storage in the butt, an A2 pistol grip, and a Knight’s Armament 12” quad rail free float handguard. The furniture shows some mild handling wear with the majority of the marks on the handguard. These marks are very common with the finish on the rail. The rail also has some Knight’s rail covers and a Knight’s QD sling cup. Overall the furniture is in Very Good to Very Good+ condition.
Magazine Quantity & Condition: This rifle includes two x 10 round magazines one Colt metal magazine and Magpul pmag. Both Magazines are in Very Good+ condition.
Type of Finish: Black
Finish Originality: Original
Bore Condition: The bore is bright and the rifling is sharp. There is no erosion in the bore. The feed ramps are smooth and shiny. The muzzle is clean. This barrel appears unfired outside of factory testing. In this writer’s opinion the bore rates 10/10.
Overall Condition: This rifle retains about 97% of its metal finish. The rifle shows minor scattered marks from handling and transport with none being notable. The markings are clear, the screw heads sharp, and the pins clean. Overall this rifle is in Very Good to Excellent condition.
Mechanics: The action functions correctly. This rifle has a California compliant lower that requires the upper and lower be separated before the magazine can be released. We did not fire this rifle. As with all used firearms, a thorough cleaning may be necessary to meet your maintenance requirements.
Box, Paperwork & Accessories: This rifle includes a pelican case, two magazines, sling, dewey rod, bore guide, harris bi-pod with a La rue QD mount, Knight’s vertical grip, and paladin gun cleaning kit.
Our Assessment: This rifle is a well-thought-out hybrid blending classic SPR (Special Purpose Rifle) attributes with modern enhancements, all built around a California-compliant Colt piston AR-15 lower. The compliance setup features a fixed magazine system that requires the separation of the upper and lower receivers to release the magazine, satisfying restrictive state regulations while maintaining core functionality. The lower sports traditional A2 furniture, a fixed stock and grip, for a stable, retro feel, and includes a high-quality Geissele trigger offering a crisp, repeatable break suited for precision shooting.
The upper, built with Centurion Arms components, is configured to replicate the MK12 SPR layout. It features an 18″ barrel with the Allen Engineering collar and brake, compatible with the AEM5 suppressor system, an iconic setup for designated marksman applications. The handguard is a Knights Armament free-float quad rail, period-correct for the MK12 style, offering rugged mounting surfaces for accessories. The rifle includes Knights flip-up backup iron sights, a PRI charging handle, a Harris bipod mounted with a LaRue QD adapter, and a Knights vertical foregrip for enhanced positional control. This build balances historical authenticity with practical upgrades, making it a serious precision platform with roots in military heritage. Please see our high quality photos via the link and best of luck with your bidding!!!-R.L.
