CMMG MOD4 SA 5.56 NATO AR-15, Fixed Carry Handle, 14.5 in Pinned/Welded to 16 in, Blackhawk Knoxx Stock
This CMMG MOD4 SA is a USA-made, 5.56 NATO, direct-impingement AR-15 featuring a fixed carry-handle upper with drum-style rear sight and an A-frame front sight post. It stands out with a 14.5 in barrel that has been pin and welded to an extended three-slot muzzle device to achieve an overall 16 in barrel length. The rifle is configured with a Blackhawk Knoxx collapsible carbine stock and classic carbine-length ribbed polymer handguards.
The receivers are 7075-T6 forged aluminum with a hardcoat anodized finish, and the upper shows the "M" forging mark on the carry-handle ear. Controls include a manual safety with SAFE/FIRE markings and a standard magazine release. The rifle uses a STANAG-pattern detachable magazine system and comes with a 20-round GI-pattern aluminum straight-body magazine.
The Blackhawk Knoxx stock provides an adjustable length of pull from 10 in to 13.5 in, paired with an A2-style polymer pistol grip for a familiar AR-15 interface. The carbine-length, two-piece ribbed polymer handguards with delta ring complete a durable, service-style configuration. Receiver markings read "CMMG, INC., FAYETTE, MO, USA."
Barrel configuration is a key feature here: the 14.5 in barrel has been pin and welded to bring overall length to 16 in, using an extended three-slot muzzle device. This setup retains the compact carbine handling while meeting the stated overall length.
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: Minor, superficial finish marks are present on the exterior. The bore is bright with a reflective surface.
What’s Included
- 1x 20-round GI-pattern aluminum straight-body AR-15 magazine
The fixed carry-handle upper with drum-style rear sight and an A-frame front sight post delivers a traditional sighting setup well-suited to a service-style configuration. The two-piece ribbed polymer carbine handguards and delta ring maintain the classic carbine profile.
The 7075-T6 forged aluminum receivers with a hardcoat anodized finish provide a robust foundation. The upper shows the "M" forging mark on the carry-handle ear, and the receiver is marked "CMMG, INC., FAYETTE, MO, USA."
Furniture and controls are practical and proven. The Blackhawk Knoxx collapsible carbine stock adjusts the length of pull from 10 in to 13.5 in. An A2-style polymer pistol grip, manual safety with SAFE/FIRE markings, and standard magazine release round out a familiar AR-15 control layout.
Chambered in 5.56mm NATO with a semi-automatic, direct impingement action, this MOD4 SA uses the STANAG-pattern detachable magazine system. Capacity is 20+1 with the included magazine.
A notable barrel setup defines this rifle: the 14.5 in barrel is fitted with a permanently attached extended three-slot muzzle device, pin and welded to achieve an overall 16 in length—exactly as configured here.