Colt FBI HRT 11.5" SOCOM barrel M4 6933 w/FSB

The Colt FBI HRT 11.5" SOCOM barrel is the correct part for building the FBI Hostage Rescue Team's signature Colt 6933 carbine — the short-barreled M4 variant that has served HRT operators since the early 2000s.

Manufactured by Colt to government specification, this barrel features the SOCOM profile contour, chrome-lined 5.56 NATO chamber and bore, 1:7 twist for heavy projectiles, and the F-marked front sight base with bayonet lug and factory-installed gas tube. The barrel carries the correct Colt CAGE-coded rollmarks and is the same part supplied on factory Colt 6933 SBR uppers.

11.5" is the defining length of the HRT carbine — short enough for close-quarters work in structures, aircraft, and buses, long enough to maintain velocity and terminal performance with M855A1 and Mk262. Paired with a suppressor-ready muzzle device, KAC RAS or Daniel Defense RIS II rail, and the appropriate HRT optic (ACOG, EOTech, or more recently the SIG ROMEO4T), it forms the basis of the most iconic HRT clone in circulation.

Requires NFA SBR or pistol lower configuration. For serious HRT clone builders — order yours today and get the exact factory part the Bureau issues.