Colt M4/M4A1 Replacement Barrel Assembly, 14.5in

This Colt barrel assembly (brand part no. SP64669) is a genuine replacement for the M4/M4A1 platform, measuring 14.5 inches and rifled with a 1:7 twist, the standard twist for 5.56 NATO/.223 Remington AR-15 barrels. It’s sold bare, with no upper receiver, gas system, or handguard included, intended for a builder replacing or upgrading a barrel on an existing upper assembly. This rifle part is built by Colt, the original manufacturer of the M4/M16 platform.

Key Specifications

• Barrel length measures 14.5 inches.
• Rifled with a 1:7 twist, the standard twist for 5.56 NATO/.223 Remington AR-15 barrels.
• Sold as a bare barrel assembly — no gas system or handguard included.
• A genuine Colt factory replacement part.

Frequently Asked Questions

Does this come with a gas block or handguard? No, it’s sold bare — you’ll need to source or reuse your own gas system and handguard.

Does a 14.5-inch barrel make my rifle an NFA short-barreled rifle? Only once it’s installed on an already-shouldered, complete rifle lower without a barrel of at least 16 inches. Building on a compatible pistol lower, or obtaining a prior ATF Form 1 approval before assembling an SBR, avoids creating an unregistered firearm.

Buy the Colt M4/M4A1 Replacement Barrel Assembly, 14.5in

A genuine Colt barrel is a straightforward way to bring a build back to factory-spec accuracy and reliability. Order this from a Lubbock, TX gun shop and our team will get your order processed right away.