Colt AR-15 A2 Gov't Model R6550 Semi-Auto Rifle 5.56mm NATO 20-inch (1988, GS-Prefix)
This Colt AR-15 A2 Gov't Model (R6550) is a USA-made, late Cold War-era rifle manufactured in 1988 with a GS-prefix serial number. It features the classic fixed carry-handle A2 upper and a 20-inch 5.56mm NATO barrel marked "C MP 5.56 NATO 1/7," along with Colt receiver markings that match the model and Hartford, Connecticut origin. The rifle is configured with iron sights and standard A2-style furniture, making it a clear example of Colt’s AR-15 A2 pattern from this period.
Condition
Overall Condition: Good condition, showing some signs of prior use and handling.
Specific Condition Notes: The firearm shows markings from previous handling and use. The bore is bright and clean. Refer to pictures.
Bore Overall Condition: Excellent - Clean, mirror finish, no signs of wear.
Bore Rifling: Excellent Rifling - Sharp lands and grooves.
What’s Included
- Soft rifle case with exterior magazine pouches
- Multi-piece cleaning rod with brushes
- 5x 30rd AR-15/M16-pattern detachable box magazines (USGI-style metal)
This R6550 is built around a direct impingement action and a fixed carry-handle A2-style upper that includes a brass deflector, forward assist, and ejection-port cover. The rear sight is the carry-handle assembly with adjustment drums, paired with an A-frame front sight base with sling swivel.
The 20-inch barrel is chambered in 5.56mm NATO (.223 Rem.) and uses a 1:7 twist. It is marked "C MP 5.56 NATO 1/7" and is fitted with a slotted birdcage-style flash suppressor.
Furniture and controls follow the A2 pattern, including a fixed stock with a trapdoor-style buttplate compartment, an A2-style pistol grip, and two-piece ribbed rifle-length synthetic handguards. Selector markings are labeled SAFE/FIRE.
Receiver markings include "COLT AR-15 A2 GOV’T MODEL CAL. .223" and "COLT’S FIREARMS DIVISION / COLT INDUSTRIES / HARTFORD, CONN. / U.S.A." The rifle is identified as a collectible example from the late 1980s and includes five USGI-style 30-round magazines and a soft case set up with exterior magazine pouches.