Proof Research 100523 AR Style 300 Blackout 12.50″ Threaded Carbon Fiber/Steel

A 300 Blackout build needs a barrel engineered for subsonic and supersonic rounds alike. This 12.50" carbon fiber and steel barrel from Proof Research delivers that versatility with a 1:7" twist rate optimized for heavier projectiles. Whether you're assembling in San Mateo or nearby, TacticCAL Gun Store in Sunnyvale handles FFL transfer in Sunnyvale for builders throughout the region.

Carbon Fiber Construction and Thermal Management

Carbon fiber barrels shed heat faster than steel-only designs, critical when running 300 Blackout through a suppressor or in rapid-fire sequences. The hybrid construction here balances weight reduction with durability. Proof Research's engineering keeps barrel harmonics stable across velocity ranges. If you're sourcing components from different sellers, our private party transfer process handles consolidation paperwork so you can focus on assembly. TacticCAL is your local gun shop in the Bay Area.

Frequently asked questions

Does the 1:7" twist work with both subsonic and supersonic 300 Blackout loads?

Yes. The 1:7" twist stabilizes heavy subsonic rounds (200–230gr) and standard supersonic loads (110–150gr) without sacrifice. This makes it the go-to choice for suppressed and unsuppressed shooting alike.

How does a 12.50" barrel affect 300 Blackout velocity compared to longer barrels?

Shorter barrels reduce muzzle velocity by roughly 100–150 fps per inch lost, but 300 Blackout was designed for this. Subsonic loads still achieve intended performance, and the compact length suits suppressed builds and short-stroke platforms.

Where can I ship an online gun order near San Jose?

TacticCAL Gun Store in Sunnyvale receives online firearm orders for buyers throughout the South Bay, including San Jose, Santa Clara, and the surrounding Bay Area. Find gun store Menlo Park at TacticCAL.