The Proof Research PR15 .300 Blackout carbon fiber AR-15 barrel (brand part number 100561) is a 16-inch drop-in direct-impingement barrel that clears the federal rifle-length minimum for a standard AR-15 build. It is wrapped from aerospace-grade carbon fiber over a 416R stainless steel liner, cutting weight by as much as 64 percent versus a comparable steel barrel, trimming weight from a caliber and length combination that can otherwise run front-heavy. This PR15 uses a carbine-length gas system and a medium .750-inch journal for a reliable, well-balanced range or duty rifle, and it ships threaded and ready to drop into a compatible AR-15 upper.

Key Specifications

• Chambered in .300 Blackout, a versatile caliber that performs well in both supersonic and subsonic loadings.
• Barrel length measures 16 inches, clearing the federal minimum rifle barrel length with no NFA paperwork required.
• Gas system is carbine-length, tuned for reliable function and a balanced feel in a standard-length AR-15.
• Journal diameter holds a medium .750-inch contour, balancing weight against barrel rigidity.
• Muzzle is threaded 5/8×24, the standard .300 Blackout thread pattern for a muzzle device or suppressor.
• Rate of twist is 1:8, stabilizing standard supersonic .300 Blackout bullet weights.
• Construction pairs a 416R stainless steel liner with a carbon-fiber wrap for faster heat dissipation.
• Weight savings run up to 64 percent lighter than a comparable steel barrel of the same contour and length.
• Ships as a drop-in barrel for compatible AR-15 pattern uppers, ready to install without additional machine work.

Frequently Asked Questions

Does this barrel require gunsmithing to install? No, it is a drop-in AR-15 pattern barrel built to install into a compatible upper without additional fitting.

Does this 16-inch length have any NFA restrictions? No. At 16 inches, this barrel meets the federal minimum rifle barrel length, so no ATF paperwork or tax stamp is required to build with it.

Is this barrel noticeably lighter than a steel AR-15 barrel? Yes, the carbon-fiber wrap can cut weight by up to 64 percent versus a comparable steel barrel of the same contour and length.

Buy the Proof Research PR15 300 Blackout 16in Barrel

Order this Proof Research PR15 .300 Blackout carbon fiber AR-15 barrel from a Lubbock, Texas gun shop for your next build. Browse more drop-in options in our AR15 barrels selection.