Aero Precision M5E1 Assembled Upper .308 Win 18″ Fluted

Aero Precision M5E1 .308 Fluted Upper Features

The M5E1 upper receiver is forged from 7075-T6 aluminum and precision machined to Aero’s exacting specifications. It features integrated handguard mounting, M4 feedramps, and laser-engraved T-marks. Standard AR .308 components are fully supported, and the upper includes the port door and forward assist pre-installed.

The Gen 2 Enhanced Handguard is built from 6061-T6 aluminum and integrates QD sling sockets at the 3, 6, and 9 o’clock positions, built-in anti-rotation tabs, and scalloped rails for improved grip. Its continuous Picatinny top rail and 1.78″ internal diameter ensure compatibility with 1.5″ suppressors and most muzzle devices.

At its core is an 18″ fluted 416R stainless steel barrel chambered in .308 Winchester, featuring a rifle-length gas system, M4 feed ramp extension, and a .750 gas block journal. The barrel is HP and MPI tested for durability and comes equipped with a standard A2 flash hider.

Aero Precision M5E1 .308 Win 18″ Fluted Specifications

• Manufacturer: Aero Precision
• Model: M5E1 Assembled Upper
• Caliber: .308 Winchester
• Barrel Length: 18″
• Barrel Profile: Fluted
• Barrel Material: 416R Stainless Steel
• Twist Rate: 1:10
• Gas System: Rifle Length
• Gas Block Journal: .750
• Flash Hider: Standard A2 (for .308)
• Receiver Material: 7075-T6 Forged Aluminum
• Feedramps: M4
• Takedown Pin Holes: .2795″
• Forward Assist: Installed
• Port Door: Installed

Gen 2 Enhanced Handguard Features:

• Handguard Material: 6061-T6 Aluminum
• Mounting: 1-Piece Free Float Design
• Anti-Rotation Tabs: Yes
• Sling Sockets: QD at 3, 6, 9 o’clock
• Top Rail: Continuous Picatinny
• Rail Profile: Milled for Grip & Aesthetics
• Inside Diameter: 1.78″
• Compatibility: Low Profile Gas Blocks, Most 1.5″ Suppressors