16" 338 ARC Upper - SHAW Barrels Stainless HBAR - 15" MLOK Rail

16" 338 ARC Upper for AR-15 with Shaw Match Grade Stainless HBAR Barrel and 15" M-LOK Rail

The 338 ARC was engineered to deliver impressive energy and suppressed performance from the AR-15 platform while maintaining reliable operation with both subsonic and supersonic ammunition. Designed around heavy projectiles, the cartridge is well suited for hunting, suppressed shooting, and compact large-caliber AR-15 configurations. This 16" 338 ARC upper features a Shaw Match Grade 416R stainless steel HBAR barrel, pistol-length gas system, A2 flash hider, and lightweight 15" free-float M-LOK handguard, giving shooters a precision-focused 338 ARC AR-15 upper with excellent durability and accessory flexibility.

Quick Glance:

Caliber: 338 ARC
Platform: AR-15
Barrel Length: 16 inches
Barrel Manufacturer: Shaw Barrels
Barrel Grade: Match Grade
Barrel Material: 416R Stainless Steel
Barrel Profile: HBAR
Barrel Finish: Matte Bead Blast
Twist Rate: 1:8 Twist
Gas System: Pistol Length
Handguard Length: 15 inches
Handguard Type: Lightweight Extended Rifle Length Free-Float M-LOK
Upper Receiver: Forged 7075-T6 Mil-Spec AR-15 Upper
Gas Block: .750" Low Profile
Muzzle Threads: 5/8x24
Muzzle Device: A2 Flash Hider
Headspace Checked: Yes – Manson GO and NO-GO Gauges
Assembly: Fully Assembled Upper Receiver Assembly

Full Details:

Upper Receiver:
AR-15 Mil-Spec forged aluminum upper receiver with forward assist and dust cover assembly installed. Forged from durable 7075-T6 aluminum and protected with a matte black MIL-A-8625 Type III, Class 2 hard coat anodized finish. The 7075-T6 construction provides greater strength than commonly used 6061 billet aluminum.

Barrel:
Shaw Match Grade 16" 338 ARC barrel manufactured from premium 416R stainless steel with an HBAR profile, matte bead blast finish, and 1:8 twist rate. Features 5/8x24 muzzle threads, a standard AR-15 barrel extension with 30 Cal. feed ramps, and is professionally headspaced using Manson GO and NO-GO gauges. This stainless 338 ARC barrel gives the upper a precision-oriented configuration while the pistol-length gas system supports dependable operation across a broad range of 338 ARC ammunition.

Handguard:
Premium lightweight 15" Extended Rifle Length narrow-profile AR-15 free-float M-LOK handguard. M-LOK slots along the 3, 6, and 9 o'clock positions provide ample room for mounting optics, lights, lasers, grips, bipods, sling attachments, and other M-LOK compatible accessories. Machined from 6061 aircraft-grade aluminum and protected with a matte black MIL-A-8625 Type III, Class 2 hard coat anodized finish.

Gas System:
Pistol-length gas system paired with a .750" low-profile gas block. The pistol-length configuration is designed to provide dependable cycling with 338 ARC ammunition while supporting both suppressed and unsuppressed AR-15 applications.

Muzzle Device:
A2 flash hider installed on the barrel's 5/8x24 muzzle threads to help reduce visible muzzle flash.

About Shaw Barrels:
Shaw Custom Barrels, also known as E.R. Shaw, was established in 1913 and is a respected manufacturer of precision rifle barrels and firearm components. Shaw Match Grade barrels are used by hunters, competitive shooters, gunsmiths, and custom rifle builders who value consistent accuracy, quality machining, and dependable performance.

Magazine Recommendation:
For best performance, Ballistic Barn recommends using 400 Legend magazines with 338 ARC uppers to maximize feeding reliability.

Headspace Checked:
Every barrel is professionally headspaced using Manson GO and NO-GO gauges to help verify proper chamber dimensions and dependable operation.

Ready to Install:
This 338 ARC upper assembly arrives fully assembled and is compatible with standard Mil-Spec dimension AR-15 lower receivers.

Important:
This product is not a firearm and will be shipped directly to you. No FFL transfer is required.

Ballistic Barn AR-15 uppers are American made and machined by manufacturers specializing in Mil-Spec AR-15 components. Every barrel is professionally headspaced using Manson GO and NO-GO gauges to help ensure dependable function, outstanding accuracy, and long-term reliability.