Colt Defense CR Series 5.56 NATO AR-15 Carbine — Colt CR-Series Lower, Geissele Upper, 14.5" Barrel, MK16 13.5" Rail, Geissele SSA Trigger, SureFire SOCOM Flash Hider
This Colt CR-series carbine pairs a Colt CR-prefix lower receiver with a Geissele Automatics upper, delivering a well-sorted AR-15 configuration in 5.56 NATO. It features a Geissele MK16 13.5" DDC free-float handguard, a factory-installed Geissele SSA two-stage trigger, ambidextrous controls, and a 14.5" threaded barrel capped with a SureFire SOCOM FH556RC-1/2-28 flash hider. The bore is excellent, and three Magpul PMAG GEN M3 magazines are included.
Condition
Overall Condition: Very good condition, showing only light, superficial signs of prior handling or use.
Bore Condition: Excellent - Clean, mirror finish, no signs of wear.
Bore Rifling: Excellent Rifling - Sharp lands and grooves.
Specific Condition Notes: The exterior shows light handling marks consistent with careful use. The finish on the receiver, barrel, and components remains strong with no visible rust, pitting, or structural damage. All controls and furniture are intact and in proper working order. The bore is bright and clean with well-defined rifling and no visible signs of corrosion or excessive wear.
What’s Included
- Colt CR-series 5.56 NATO carbine as configured (Colt Carbine lower with Geissele upper installed)
- Three 30-round Magpul PMAG GEN M3 polymer magazines (Window variant shown)
The lower receiver is a Colt CR-series unit with the CARBINE CAL. 5.56 MM rollmark, CR-prefix serial, selector markings SAFE/FIRE, and a QR-style code on the magwell. The forged flat-top upper includes a forward assist, ejection port cover, and a T-marked Picatinny top rail. The platform feeds from STANAG-pattern detachable box magazines and has a maximum capacity of 30+1.
The Geissele Automatics upper is matched with a Geissele Super Modular Rail MK16, 13.5" length, finished in DDC. This free-float M-LOK handguard is 7000-series aluminum and carries NSN 1005-01-672-4797. It provides a continuous T-marked top rail with accessory Picatinny at 6 o’clock for direct accessory mounting.
The 14.5" barrel is threaded 1/2-28 and fitted with a SureFire SOCOM FH556RC-1/2-28 flash hider bearing the SF logo and partial NSN. The rifle uses a semi-automatic, direct-impingement operating system and a hardcoat-anodized finish over forged 7075-T6 aluminum receivers.
Controls and furniture are set up for practical handling: a Geissele SSA two-stage trigger is installed, along with an ambidextrous safety selector and an ambidextrous charging handle with a tan anodized finish. B5 Systems furniture includes an adjustable carbine stock and a B5 pistol grip, with an adjustable length of pull of approximately 11.5"–14.5".
Included magazines are Magpul PMAG GEN M3 30-round units, with a Window variant present as shown. The overall configuration emphasizes proven Colt foundation components paired with premium Geissele upgrades and a SureFire SOCOM-series muzzle device.