Colt M4 Carbine 5.56mm SBR, 14.5” Chrome-Lined M4 Contour Barrel (Flat-Top), Matte Black

Overview

The Colt M4 Carbine Model 6921 is a lightweight, rapid-deployment semi-automatic rifle engineered for mobility, fast target acquisition, and dependable 5.56mm performance. Built on the combat-proven M4 platform, this flat-top Short Barrel Rifle configuration pairs a 14.5” chrome-lined M4 contour barrel with a Magpul folding rear sight and rugged construction to deliver the balance, range, and reliability operators expect.

Key Features

• Designed for lightweight mobility, speed of target acquisition, and potent firepower capability.
• Combat-proven M4 platform engineering adapted for law enforcement, tactical teams, and responsible civilian owners.
• 14.5” chrome-lined M4 contour barrel with A2 flash suppressor for proven durability and consistent accuracy.
• Flat-top receiver with Magpul folding back-up rear sight and standard front sight post for reliable iron sight use or optic mounting.
• Handguard with dual aluminum shielding for improved heat protection under sustained fire.
• Black anodized hardcoat finish for long-term corrosion resistance and low-observable appearance.
• Gas-operated semi-automatic action with 1:7” right-hand twist optimized for modern 5.56/223 projectiles.

Specifications

• Model: Colt M4 Carbine, Model 6921 (flat-top)
• Caliber: .223 Remington / 5.56 NATO
• Barrel: 14.5” chrome-lined M4 contour with A2 flash suppressor (not pinned in this configuration)
• Twist Rate: 1:7” RH
• Operating System: Gas-operated semi-automatic
• Receiver: Flat-top for optics; Magpul folding back-up rear sight included
• Handguard: Dual aluminum shielding for enhanced heat protection
• Sights: Magpul folding rear sight; standard front sight post (F height)
• Finish: Black anodized hardcoat
• Intended Use: Tactical deployment, patrol, rapid-response, and general purpose 5.56 applications

Applications & Notes

• Ideal for tactical teams, law enforcement, and civilian shooters who require a compact, capable 5.56 platform for close-quarters and mid-range engagements.
• Flat-top receiver allows quick mounting of optics, red dots, and other mission-specific accessories.
• Verify local, state, and federal laws and transfer requirements prior to purchase or transfer; some barrel/overall-length configurations may be subject to special regulations.

Care & Maintenance

• Routinely clean and inspect the bore and gas system after use; follow Colt’s recommended maintenance intervals.
• Keep rails, barrel extensions, and gas ports free of obstructions; lightly lubricate contact surfaces for reliable operation.
• Store unloaded in a secure, dry location and comply with all applicable storage and transport laws.