$749.54
Availability: In Stock
Current Stock: Out of stock
The Aero Precision M5E1 complete upper receiver in .308 Winchester is a purpose-built assembly for shooters who demand precision and reliability in a modern AR-platform rifle. This 18-inch stainless steel upper comes fully assembled with a Gen 2 Enhanced Handguard, gas block, gas tube, and flash hider—everything you need except a bolt carrier group and charging handle. Whether you're building a mid-range hunting rifle, a precision target gun, or a versatile patrol rifle, the M5E1 delivers the quality engineering Aero is known for in a caliber built for serious downrange performance.
The upper receiver itself is forged from 7075-T6 aluminum and precision-machined to tight tolerances, with M4 feedramps and a forward assist and port door already installed. The receiver's handguard mounting platform is forged directly into the upper, ensuring rock-solid stability. The 15-inch Gen 2 Enhanced Handguard features M-LOK attachment, quick disconnect sling sockets at 3, 6, and 9 o'clock positions, and a continuous Picatinny top rail with an internal diameter of 1.78 inches—compatible with most muzzle devices and 1.5-inch suppressors. The handguard's scalloped rail design and milled grip surfaces blend ergonomic function with clean aesthetics.
The 18-inch barrel is hammer-forged from 416R stainless steel with a 1/10 twist rate optimized for .308 Winchester. It features a fluted profile for reduced weight and improved heat dissipation, a .750-inch gas block journal, and a rifle-length gas system. The barrel is M4 feed ramp extended and has been HP and MPI tested for consistency. Out of the box, it ships with Aero's standard .308 A2 birdcage flash hider. The whole package lands in Flat Dark Earth, a practical finish that works in field or range environments.
This is a no-compromise assembled upper from a manufacturer that understands what modern shooters expect. Aero's attention to detail—from the laser-engraved T-marks to the anti-rotation tabs on the handguard—shows throughout. If you're ready to complete a serious .308 build, this upper handles the foundation work so you can focus on your triggers, stocks, and optics.
| Caliber | .308 Winchester |
| Barrel Length | 18 inches |
| Barrel Material | 416R Stainless Steel, fluted |
| Barrel Twist | 1/10 |
| Gas System | Rifle length |
| Gas Block Journal | .750 inch |
| Upper Receiver Material | 7075-T6 Aluminum |
| Handguard Length | 15 inches |
| Handguard Material | 6061-T6 Aluminum |
| Handguard Attachment | M-LOK |
| Top Rail | Continuous Picatinny, 1.78" ID |
| Takedown Pin Holes | .2795 inch |
| Flash Hider | .308 A2 Birdcage |
| Finish | Flat Dark Earth (FDE) |
| Included Components | Upper receiver, handguard, gas block, gas tube, flash hider |
| Not Included | Bolt carrier group, charging handle |
The M5E1 upper comes fully assembled with everything except a bolt carrier group and charging handle. You'll need to source those separately to complete your build. Once you have a carrier and handle, you can integrate this upper onto a compatible .308 lower receiver.
The M5E1 is designed for the AR-10 platform and accepts standard AR .308 components. Verify that your lower receiver is chambered and built for .308 Winchester and is compatible with the M5E1 upper's takedown pin specifications (.2795-inch holes).
Yes. The handguard has an internal diameter of 1.78 inches, which is compatible with most muzzle devices and 1.5-inch suppressors. The rifle-length gas system and included A2 flash hider support suppressed fire, though you may want to consider an adjustable gas block if running a suppressor regularly.
Yes. The M5E1 accepts standard AR .308 components, including the gas block and tube configuration. The barrel comes installed and tested, but if you want to swap it in the future, any standard .308 barrel with the appropriate gas journal and feedramp design will work.
SKU: 126797498 • Weight: 5.6oz
Availability: In Stock
Current Stock: Out of stock
The Aero Precision M5E1 complete upper receiver in .308 Winchester is a purpose-built assembly for shooters who demand precision and reliability in a modern AR-platform rifle. This 18-inch stainless steel upper comes fully assembled with a Gen 2 Enhanced Handguard, gas block, gas tube, and flash hider—everything you need except a bolt carrier group and charging handle. Whether you're building a mid-range hunting rifle, a precision target gun, or a versatile patrol rifle, the M5E1 delivers the quality engineering Aero is known for in a caliber built for serious downrange performance.
The upper receiver itself is forged from 7075-T6 aluminum and precision-machined to tight tolerances, with M4 feedramps and a forward assist and port door already installed. The receiver's handguard mounting platform is forged directly into the upper, ensuring rock-solid stability. The 15-inch Gen 2 Enhanced Handguard features M-LOK attachment, quick disconnect sling sockets at 3, 6, and 9 o'clock positions, and a continuous Picatinny top rail with an internal diameter of 1.78 inches—compatible with most muzzle devices and 1.5-inch suppressors. The handguard's scalloped rail design and milled grip surfaces blend ergonomic function with clean aesthetics.
The 18-inch barrel is hammer-forged from 416R stainless steel with a 1/10 twist rate optimized for .308 Winchester. It features a fluted profile for reduced weight and improved heat dissipation, a .750-inch gas block journal, and a rifle-length gas system. The barrel is M4 feed ramp extended and has been HP and MPI tested for consistency. Out of the box, it ships with Aero's standard .308 A2 birdcage flash hider. The whole package lands in Flat Dark Earth, a practical finish that works in field or range environments.
This is a no-compromise assembled upper from a manufacturer that understands what modern shooters expect. Aero's attention to detail—from the laser-engraved T-marks to the anti-rotation tabs on the handguard—shows throughout. If you're ready to complete a serious .308 build, this upper handles the foundation work so you can focus on your triggers, stocks, and optics.
| Caliber | .308 Winchester |
| Barrel Length | 18 inches |
| Barrel Material | 416R Stainless Steel, fluted |
| Barrel Twist | 1/10 |
| Gas System | Rifle length |
| Gas Block Journal | .750 inch |
| Upper Receiver Material | 7075-T6 Aluminum |
| Handguard Length | 15 inches |
| Handguard Material | 6061-T6 Aluminum |
| Handguard Attachment | M-LOK |
| Top Rail | Continuous Picatinny, 1.78" ID |
| Takedown Pin Holes | .2795 inch |
| Flash Hider | .308 A2 Birdcage |
| Finish | Flat Dark Earth (FDE) |
| Included Components | Upper receiver, handguard, gas block, gas tube, flash hider |
| Not Included | Bolt carrier group, charging handle |
The M5E1 upper comes fully assembled with everything except a bolt carrier group and charging handle. You'll need to source those separately to complete your build. Once you have a carrier and handle, you can integrate this upper onto a compatible .308 lower receiver.
The M5E1 is designed for the AR-10 platform and accepts standard AR .308 components. Verify that your lower receiver is chambered and built for .308 Winchester and is compatible with the M5E1 upper's takedown pin specifications (.2795-inch holes).
Yes. The handguard has an internal diameter of 1.78 inches, which is compatible with most muzzle devices and 1.5-inch suppressors. The rifle-length gas system and included A2 flash hider support suppressed fire, though you may want to consider an adjustable gas block if running a suppressor regularly.
Yes. The M5E1 accepts standard AR .308 components, including the gas block and tube configuration. The barrel comes installed and tested, but if you want to swap it in the future, any standard .308 barrel with the appropriate gas journal and feedramp design will work.
SKU: 126797498 • Weight: 5.6oz