This Colt 5.56mm NATO Barrel (brand part no. SP401757) is built to an 11.5-inch length with a 1:7 twist rate, giving compact-carbine builders a proven barrel from a name trusted across military and law-enforcement rifle systems. The 1:7 twist rate stabilizes the full range of common 5.56 and .223 bullet weights, including heavier match and specialty loads, and the black finish matches standard AR-15 and M4 builds. It’s a solid choice for finishing out a compact upper or replacing a worn factory barrel.
Key Specifications
- It’s Chambered for 5.56mm NATO for reliable function across mil-spec ammunition.
- An 11.5-Inch Length suits compact-carbine and close-quarters builds.
- A 1:7 Twist Rate stabilizes heavier common 5.56 bullet weights.
- A Black Finish matches standard AR-15/M4 builds.
- It’s Manufactured by Colt, trusted across military and law-enforcement platforms.
Frequently Asked Questions
What twist rate does this barrel use? 1:7.
What length is this barrel? 11.5 inches.
Buy the Colt 5.56mm NATO Barrel
Finish out a compact-carbine build or replace a worn barrel with this Colt 5.56mm NATO barrel. Order it from our Lubbock, Texas gun shop for fast, insured shipping to your FFL, and add it to your rifle parts build.
