CMMG Mk4 AR-15 Semi-Auto Rifle in 300 AAC Blackout with 16" Barrel and UTG Scope
This CMMG Mk4 is an AR-15 platform rifle chambered in 300 AAC Blackout (7.62x35mm) with a 16" barrel and a 1:7 twist. It features a flat-top upper with a Picatinny rail and a quad-rail handguard with numbered index markings for consistent accessory placement. Receiver markings include the CMMG logo/wordmark, "MK-4", and "MULTI", with the barrel marked "CMMG WASP" and "300 AAC BLK 1:7".
Condition
Overall Condition: Excellent condition, showing only faint signs of any prior use or handling.
Bore Condition: Excellent - Clean, mirror finish, no signs of wear.
Bore Rifling: Excellent Rifling - Sharp lands and grooves.
Specific Condition Notes: The firearm shows little sign of prior use and is in excellent condition and function.
What's Included
- UTG tube-style riflescope installed with flip-up lens caps, mounted to the upper receiver Picatinny rail
Built around CMMG's Mk4 receiver set, this rifle uses a semi-automatic, direct impingement action and a two-position safety selector marked SAFE/SEMI. The controls and layout follow the AR-15 pattern, with a flat-top upper that provides a continuous mounting surface for optics.
The 16" barrel is clearly marked for 300 AAC Blackout and a 1:7 twist, and it is paired with a slotted flash-hider-style muzzle device. The bore is described as clean with a mirror finish and excellent rifling, matching the overall excellent condition noted for the rifle.
Up front, the quad-rail handguard includes numbered index markings, making it easy to return accessories to consistent positions. The rifle also has an adjustable, collapsible M4-style stock and a polymer pistol grip, keeping the setup aligned with a familiar AR configuration.
A UTG tube-style riflescope is already installed on the upper receiver Picatinny rail and includes flip-up lens caps. This provides a magnified optic setup as pictured and described, without requiring additional mounting hardware to begin using the rifle in its current configuration.