Brownells Ar-15 5.56 M4 Barrel Group 16'' 1-7 Twist, Carbine Gas

The Brownells AR-15 5.56 M4 barrel group is a complete, ready-to-install carbine barrel assembly built to military contractor standards. This 16-inch barrel comes with the slip ring, F-Marked front sight base, and handguard cap already assembled—saving you time and ensuring everything fits right out of the box. If you're building or rebuilding an M4-pattern AR, this is a no-fuss foundation that lets you focus on the rest of your rifle.

Built from 4150 chrome moly steel with a hard chrome bore and button rifling, this barrel is individually inspected and high pressure tested to ensure absolute reliability. The 1-7 twist rate is versatile enough to stabilize 62-grain ammunition and heavier projectiles, making it suitable for general shooting, training, and hunting applications where a carbine platform makes sense. Every barrel is magnetic particle inspected and gauged to catch any defects before it ships.

The round handguard cap is correct for the M4 carbine length, and the chamber is marked for 5.56x45mm NATO. Whether you're an AR builder looking for a proven, no-nonsense barrel or someone restocking a trusted platform, the Brownells assembly takes the guesswork out of sourcing individual components and getting them to work together.

Key Features

• 16-inch carbine-length barrel for M4-pattern AR platforms
• Hard chrome bore with button rifling for durability and accuracy
• 1-7 twist rate stabilizes 62-grain and heavier ammunition
• 4150 chrome moly steel construction
• Pre-installed slip ring, F-Marked front sight base, and round handguard cap
• High pressure tested and magnetic particle inspected
• 5.56x45mm NATO chamber
• Government contractor quality standards

Specifications

Frequently Asked Questions

What ammunition does this AR-15 barrel shoot?

The 5.56x45mm NATO chamber and 1-7 twist are rated for 62-grain and heavier ammunition. This gives you flexibility with mid-range and heavier loadings while maintaining stable, reliable performance.

Is this barrel assembly ready to install?

Yes. The slip ring, F-Marked front sight base, and round handguard cap come pre-installed. You can mount it directly onto a compatible upper receiver without additional assembly work.

What makes this a government-quality barrel?

Brownells manufactures these assemblies to the same standards as a US Government contractor, then inspects each barrel with high pressure testing and magnetic particle inspection to ensure zero defects before shipping.

Will this work on my existing AR upper?

This is an M4 carbine-length barrel assembly designed for AR-15 platform uppers that accept standard carbine-length barrels. Check your upper receiver specifications to confirm compatibility.