The Colt M4 Carbine (CR6920) is a semi-automatic rifle chambered in 5.56x45mm NATO with a 16.1-inch barrel and a four-position adjustable stock. It holds 30+1 rounds and weighs 6.9 lbs. The overall length adjusts between 32.0" and 35.5". A2 front sights and Magpul rear sights are included. The receiver is aluminum alloy, and a muzzle compensator ships with the rifle. 
 

Key Specifications 

• Manufacturer: Colt Firearms 
• Model: M4 Carbine (CR6920) 
• Caliber: 5.56x45mm NATO 
• Action Type: Semi-Automatic 
• Capacity: 30 rounds + 1 in chamber 
• Barrel Length: 16.1 inches 
• Weight: 6.9 lbs. 
• Finish Color: Black 
• Overall Length: Adjustable between 32.0" - 35.5" 
• Safety Mechanism: Cross Bolt Safety 
   

Detailed Features 

The four-position stock adjusts for different shooters and shooting positions without tools. A2 front sights are a proven design that hold zero reliably; the Magpul rear sight adds windage and elevation adjustment. The aluminum alloy receiver keeps weight in check while handling the stresses of 5.56 NATO without issue. 
 
The muzzle compensator reduces recoil and muzzle rise, which helps with faster follow-up shots. The cross bolt safety is a clean, simple mechanism that works reliably. 
 

Usage Scenarios 

• Home defense where the 5.56 caliber, 30+1 capacity, and adjustable stock suit a range of users in the same household. 
• Competitive shooting where the platform's established ergonomics and widespread aftermarket support make setup straightforward. 
• Training and general range use where the rifle's familiarity and parts availability are practical advantages.

The Colt M4 CR6920 is a well-regarded rifle in the AR-15 category. Owners consistently praise reliability and accuracy, and the Colt name carries genuine credibility in this platform. The lightweight design and adjustable stock work well together for extended use, and the rifle's wide customization options are a frequent positive — the aftermarket for this platform is as deep as any rifle in production.

Price is the most common friction point. Some owners feel that equivalent reliability and accuracy is available at lower cost from other manufacturers, and that the Colt premium requires justification beyond brand recognition. Availability issues have been reported by some buyers, particularly during high-demand periods. Minor complaints about finish durability over time and specific small components appear occasionally but are not widespread. The overall sentiment is clearly positive — the CR6920 holds its position as a reference-grade civilian AR-15.