Brownells Brn-4 5.56X45 14.5'' Medium Chrome Lined Barrel Phosphate

The Brownells BRN-4 5.56x45 14.5" Medium Chrome Lined Barrel is purpose-built for shooters assembling HK 416 compatible uppers who want a balance between durability and handling. This barrel is machined by Faxon to work seamlessly with early-generation HK 416 upper receivers and components, making it an ideal choice if you're running a BRN-4 platform build. The 14.5-inch length strikes a practical middle ground for intermediate-range shooting, patrol-style setups, or precision rifle work without the extra weight of a longer profile.

Built with a medium contour profile, this barrel sheds unnecessary weight compared to the heavier variants while maintaining the rigidity you need for consistency. The button-rifled bore comes with a 1-7 twist rate, proven across a wide range of 5.56x45mm NATO and .223 Remington ammunition. Chrome lining inside the bore and chamber delivers superior corrosion resistance and extends barrel life, especially valuable if you shoot regularly or in demanding conditions. The phosphate finish on the exterior is tough, low-maintenance, and period-correct for modern piston-gun aesthetics.

Threading is standard ½-28 at the muzzle, so you can attach any suppressor, muzzle brake, or flash hider in your collection. Installation is straightforward with the BRN-4 barrel nut (torque to 50–80 ft/lbs), and the extended barrel extension provides a robust fit to the upper receiver. All BRN-4 barrels accept the same piston rod assembly, so your gas tube length stays consistent; just pair this barrel with the appropriate gas block for the 14.5-inch length and you're ready to go.

Key Features

• 14.5-inch medium profile optimizes weight and handling without sacrificing rigidity
• Chrome-lined bore and chamber for extended service life and corrosion resistance
• Button-rifled with 1-7 twist for reliable 5.56x45mm NATO and .223 Remington accuracy
• ½-28 muzzle threads accommodate standard suppressors and muzzle devices
• Phosphate exterior finish—durable, low-maintenance, and easy to clean
• HK 416 compatible; works with BRN-4 upper receivers and components
• Standard gas tube length across all BRN-4 barrels for simplified parts commonality

Specifications

Frequently Asked Questions

Is this barrel compatible with standard AR-15 uppers?

No. This barrel is specifically designed for early-generation HK 416 upper receivers and the BRN-4 platform. It uses a different barrel extension than standard AR-15 barrels and requires the BRN-4 barrel nut for proper installation.

What gas block should I use with this 14.5-inch barrel?

Pair this barrel with the correct gas block for its length. Refer to the gas block compatibility references in the BRN-4 lineup (models 078-000-708 or 078-000-709 for your barrel length) and ensure you have the gas block coil pins (430-103-127) for assembly.

Will this barrel shoot .223 Remington ammunition?

Yes. The barrel is chambered in 5.56x45mm NATO, which safely fires both 5.56x45mm NATO and .223 Remington cartridges.

What piston rod assembly does this barrel use?

All BRN-4 barrels use the same piston rod assembly (078-000-644), regardless of barrel length. No need to source different gas system components across lengths.