AR barrels for AR-15 and AR-10/.308 builds, across calibers from .223/5.56 and 300 Blackout to 7.62×39, 9mm, 6.5 Creedmoor, and 6mm ARC. Most are 4150 chrome-moly-vanadium steel with a nitride finish, with stainless options, in a range of lengths and twist rates. Pick your caliber, then match length, twist, gas system, and thread pitch to your build.

Barrels

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Choosing an AR Barrel

Caliber

Start with the cartridge you're building: .223/5.56 for general-purpose AR-15s, 300 Blackout for short/suppressed builds, 7.62x39 for the AK round, 9mm for pistol-caliber carbines, and .308/6.5 Creedmoor/6mm ARC for large-frame and precision use. Each caliber has its own subcategory.

Barrel length and gas system

Barrel length drives velocity and handling, and it must match the gas system length — carbine gas for short barrels, mid-length for ~14–16", rifle-length for ~18–20". A correctly matched gas length runs softer and more reliably.

Twist rate

Twist stabilizes bullet weight: faster twists (e.g., 1:7) stabilize heavier, longer bullets; slower twists (e.g., 1:9) suit lighter bullets. Match the twist to the loads you'll shoot.

Profile, steel, and finish

Lighter profiles carry easier; heavier/bull profiles resist heat for sustained fire. Most barrels are 4150 chrome-moly-vanadium steel with a nitride finish; 416 stainless options favor accuracy. AR-15 barrels typically have M4 feed ramps.

Thread pitch

Muzzle threads must match your muzzle device — usually 1/2x28 for .223/5.56 and 9mm, 5/8x24 for .308 and 300 Blackout. Confirm the thread on the listing.

Frequently Asked Questions

What gas system length do I need?

Match it to barrel length — carbine for ~10–14", mid-length for ~14–16", rifle for ~18–20".

Do you need an FFL to buy a barrel?

No. A barrel isn't a regulated firearm part, so it ships without an FFL.