The Colt AR15A4 is a semi-automatic rifle chambered in 5.56mm NATO / .223 Remington. It uses the classic A4 configuration with a fixed carry handle, A2 front sight post, and a 20-inch barrel. 
 

Key Specifications 

• Model: AR15A4 
• Caliber: 5.56mm NATO / .223 Remington 
• Barrel Length: 20 inches 
• Overall Length: 39.5 inches 
• Weight: 7.7 lbs 
• Capacity: 30+1 rounds (detachable magazine) 
• Finish Color: Black (Black Manganese Phosphate) 
• Action Type: Semi-Automatic 
• Safety Mechanism: Manual Thumb Safety 
   

Detailed Features: 

The 20-inch barrel is made from 4150 Chrome Moly Vanadium steel with a Black Manganese Phosphate finish. A2 front sight post and adjustable rear sights in the fixed carry handle give you a longer sight radius than carbine-length alternatives, useful for precise iron-sight shooting. The 7075-T6 aluminum receiver is standard for the AR platform, keeping weight in check while maintaining durability. Single-stage trigger operates cleanly. Right-hand grip is the standard A2 pistol grip. Fires both .223 Remington and 5.56mm NATO. The 30-round STANAG magazine is widely available.

Owners of the Colt AR15A4 in 5.56 NATO report strong satisfaction overall, driven primarily by Colt's reputation and the rifle's consistent performance.

Reliability is the most cited strength. Owners report dependable function across diverse conditions and use cases. Build quality gets consistent praise for materials and fit, and accuracy out of the box is frequently mentioned as meeting or exceeding expectations. The 30-round magazine capacity and wide availability of compatible magazines are noted as practical positives. The classic black finish is appreciated for its functional look.

The most common criticism is price. Colt commands a premium that some buyers question when similar AR-platform performance is available at lower cost from other manufacturers. Weight (7.7 lbs with a 20" barrel) comes up for those who prefer lighter carbine configurations. Occasional discussions touch on whether the premium over comparable rifles is justified, though most owners who buy it feel it is.