20" 243 Winchester Upper with Aero Precision M5 Receiver - 4150 Chrome Moly HBAR Barrel and 15" M-LOK Rail
This 20" 243 Winchester upper features a 4150 chrome moly steel HBAR barrel with a parkerized finish and 1:8 twist rate. Built around an Aero Precision M5 .308 upper receiver, the assembly combines a rifle-length gas system, 15" free-float M-LOK handguard, and A2 flash hider. The 243 Winchester cartridge is widely used for varmint hunting, predator hunting, deer hunting, and target shooting. Each upper is assembled in Texas and individually checked for proper headspace using Manson GO and NO-GO gauges.
Quick Glance:
Caliber: 243 Winchester
Platform: AR-10 - Aero Precision M5
Barrel Length: 20 inches
Barrel Material: 4150 Chrome Moly Steel
Barrel Profile: HBAR
Barrel Finish: Parkerized
Twist Rate: 1:8 Twist
Barrel Extension: DPMS Pattern with .308 Feed Ramps
Gas System: Rifle Length
Handguard Length: 15 inches
Handguard Type: Gen 3 Free-Float M-LOK
Upper Receiver: Aero Precision M5 .308 - 7075-T6 Aluminum
Upper Receiver Finish: Matte Black Hardcoat Anodized
Gas Block: .750" Low Profile Nitride
Muzzle Threads: 5/8x24
Muzzle Device: A2 Flash Hider with Crush Washer
Lower Receiver Compatibility: Aero Precision M5 .308 Only
Headspace Checked: Yes - Manson GO and NO-GO Gauges
Assembly: Fully Assembled in Texas
Full Details:
Upper Receiver:
Aero Precision M5 .308 upper receiver manufactured from 7075-T6 aluminum with a matte black hardcoat anodized finish. Features forward assist and dust cover assemblies installed. The receiver is designed for use with Aero Precision M5 .308 lower receivers.
Barrel:
20" 243 Winchester barrel manufactured from 4150 chrome moly steel with an HBAR profile, parkerized finish, and 1:8 twist rate. Features 5/8x24 muzzle threads and a DPMS-pattern barrel extension with .308 feed ramps. Each barrel is individually checked for proper headspace using Manson GO and NO-GO gauges.
Handguard:
Gen 3 15" extended rifle-length narrow-profile AR-10 free-float M-LOK handguard manufactured from 6061 aircraft-grade aluminum. M-LOK attachment slots are positioned along the 3, 6, and 9 o'clock positions, providing mounting space for compatible accessories. Features a matte black MIL-A-8625 Type III, Class 2 hard coat anodized finish.
Gas System:
Rifle-length gas system paired with a .750" low-profile gas block featuring a nitride finish.
Muzzle Device:
A2 flash hider installed with a crush washer on 5/8x24 muzzle threads.
Compatibility:
This upper assembly is configured with an Aero Precision M5 .308 upper receiver and is intended for use with Aero Precision M5 .308 lower receivers only. The barrel uses a DPMS-pattern barrel extension, but this does not establish compatibility with other manufacturers' lower receivers. AR-10 receiver dimensions are not universally standardized.
Included Components:
The assembly includes the Aero Precision M5 .308 upper receiver, 20" 4150 chrome moly steel HBAR barrel chambered in 243 Winchester, 15" Gen 3 M-LOK handguard, rifle-length gas system, .750" gas block, and A2 flash hider.
Important:
This upper receiver assembly is not classified as a firearm when sold separately and does not require an FFL transfer under federal law. Applicable state and local restrictions may vary.
Ballistic Barn AR-10 upper assemblies are assembled in Texas using components manufactured for large-frame AR platforms. Each barrel is individually checked for proper headspace using Manson GO and NO-GO gauges before shipment.
