10.5″ AR-15 Barrel — 4150 CMV, M4 Contour, 1:7 Twist (5.56 NATO)

Overview:
This 10.5″ AR-15 pistol barrel is manufactured from high-grade 4150 Chrome Moly Vanadium (CMV) and machined to precise tolerances for reliable performance in short-barrel AR builds. Featuring an M4 contour, 1:7 twist, carbine-length gas system, .750″ gas journal, M4 feed ramps, and 1/2-28 muzzle threads, this barrel is chambered in 5.56 NATO (safe to shoot .223 as well) and proudly made in the USA.

Key Features

• Caliber / Chamber: 5.56 NATO (also shoots .223)
• Length: 10.5 inches
• Material: 4150 Chrome Moly Vanadium (CMV)
• Profile: M4 contour with M4 feed ramps
• Twist Rate: 1:7 — optimized for stabilizing heavier 5.56/.223 bullets
• Gas System: Carbine-length gas system
• Gas Block Journal: .750″ (fits standard .750 gas blocks)
• Muzzle: 1/2-28 threaded for standard muzzle devices
• Made: USA

Why this barrel?

The 1:7 twist rate pairs perfectly with a wide range of bullet weights (particularly 55–77 gr and heavier match projectiles), making this a versatile short-barrel option for CQB, personal defense, or a lightweight patrol/staff build. The M4 contour gives a good balance of strength and weight while the .750” gas journal accepts common carbine gas blocks for easy gas-system assembly.

Compatibility & Build Notes

• Designed for AR-15 Pistol uppers in short-barrel configurations — ensure you understand SBR/NFA rules in your jurisdiction before assembling as a rifle. (Check ATF guidance or local rules if unsure.)
• Fits standard AR barrel nuts, .750″ gas blocks, and 1/2-28 muzzle devices.
• We recommend a qualified gunsmith for headspace checks and final assembly if you are not experienced with upper builds.

Installation & Accessories

Pair this barrel with our carbine-length gas blocks, gas tubes, and compatible handguards for a clean build. Browse related barrels and short-barrel components in our AR barrels categories and short-barrels collection to complete your upper assembly.

• See other 5.56/.223 barrels & specs.
• Short barrels category (10.5″, 11.5″, 12.5″, etc.).
• How to choose an AR-15 barrel — guide

Specs (Quick Reference)

Note: Always confirm local/state laws and NFA rules relating to SBRs before building or registering. Contact Mid State Firearms with fitment or compatibility questions, or browse our AR parts to complete your build.

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