Colt Defense M4A1 Carbine 5.56 NATO — PROPERTY OF U.S. GOVT. Rollmark, 14.5 in Barrel, Knights Armament Quad-rail Installed, MaTech 200–600 m Rear Sight
This Colt Defense M4A1 Carbine stands out for its "PROPERTY OF U.S. GOVT." rollmark, CR-prefix serial number, and Colt Defense Hartford markings, all paired with a correct-feature 14.5 in 1:7-twist 5.56 NATO barrel bearing the 13629 CAGE and M P marks. It is configured with a Knights Armament M4 RAS quad-rail, ribbed KAC panels, and a vertical foregrip, plus a MaTech USGI 200–600 m flip-up rear sight. A Data Matrix/UID code is present on the magwell, and the flat-top upper carries T-marked Picatinny rail indexing.
Condition
Overall Condition: Very good condition, showing only light, superficial signs of prior handling or use.
Bore Overall Condition: Excellent - Clean, mirror finish, no signs of wear.
Bore Rifling: Excellent Rifling - Sharp lands and grooves.
Specific Condition Notes: This firearm is in great shape. There are minor, superficial scratches and blemishes from light handling.
What’s Included
- 3x 30-round magazines
- USGI aluminum magazines marked Colt and Brownells
- TangoDown polymer magazine
- Knights Armament M4 RAS drop-in quad-rail (installed)
- Knights Armament ribbed rail panels (installed)
- Vertical foregrip (installed)
- MaTech USGI 200–600 m flip-up rear sight (installed)
The lower receiver is marked "PROPERTY OF U.S. GOVT. / M4A1 CARBINE / CAL 5.56 MM" with the Colt rampant pony and "COLT DEFENSE HARTFORD, CONN. U.S.A." A CR-prefix serial number and a Data Matrix/UID code on the magwell add detail collectors look for on Colt Defense–era M4A1 carbines.
The 14.5 in barrel is correctly rollmarked "13629 M P 5.56 NATO 1/7," indicating the Colt CAGE code and magnetic particle testing, with a 1:7 twist for standard 5.56 NATO projectiles. It uses a carbine-length gas system and is fitted with an A2 flash suppressor.
A Knights Armament Quad-rail is installed: the KAC M4 RAS drop-in quad-rail with KAC markings, paired with ribbed rail panels and a vertical foregrip. The rifle retains the fixed A2 front sight base with bayonet lug and sling loop.
The flat-top upper includes a T-marked Picatinny rail, and sights consist of a MaTech USGI 200–600 m flip-up rear sight matched to the fixed A2 front. The rifle uses the STANAG magazine interface with a 30+1 capacity and features a collapsible 6-position stock, A2 pistol grip, aluminum receivers, black finish, and a manual safety. Operation is semi-automatic, direct impingement on the AR-15 platform.