
Availability: In Stock
Current Stock: Out of stock
The Aero Precision M5E1 complete upper 18" .308 stainless steel fluted receiver is a fully assembled platform built for shooters who want a battle-ready .308 AR without sourcing a dozen separate components. This upper comes ready to mate with your .308 lower—no BCG or charging handle needed—with a free-floated handguard, gas tube, flash hider, and gas block all installed and tuned. It's the kind of no-nonsense upper that works equally well for precision rifle duties at distance or duty-grade reliability on the range.
The receiver itself is forged from 7075-T6 aluminum and precision-machined to Aero's exacting standards. It features M4 feedramps, standard AR .308 component compatibility, forward assist and port door already installed, and quick-disconnect sling sockets at the 3, 6, and 9 o'clock positions on the handguard for flexible carry options. The Gen 2 Enhanced M-LOK handguard is machined from 6061-T6 aluminum with a 1.78" inside diameter that plays nicely with most muzzle devices and 1.5" suppressors, and it floats free for consistent barrel harmonic behavior.
The barrel is where things get serious: 18 inches of 416R stainless steel with a 1/10 twist, drilled for rifle-length gas and a .750 gas block journal. Fluting saves weight without sacrificing rigidity. The barrel is HP and MPI tested to Aero's standards, so you're getting proven metallurgy, not guesses. It ships with a standard .308 A2 birdcage flash hider installed, low-profile gas block compatible, and rifle-length gas tube ready to cycle your rounds reliably.
This is a complete upper for shooters who respect precision and reliability in equal measure—whether you're building a mid-range hunting rifle, a distance-shooting platform, or a duty-grade .308 AR that simply needs to work.
| Caliber | .308 Winchester |
| Barrel Length | 18" |
| Barrel Material | 416R Stainless Steel, fluted |
| Twist Rate | 1/10 |
| Gas System | Rifle length |
| Gas Block Journal | .750" |
| Receiver Material | 7075-T6 Aluminum |
| Receiver Type | M5E1 |
| Handguard | Gen 2 Enhanced M-LOK, 15", free-floated |
| Handguard Material | 6061-T6 Aluminum |
| Handguard Internal Diameter | 1.78" |
| Flash Hider | .308 A2 Birdcage |
| Included | Upper receiver, handguard, gas block, gas tube, flash hider (BCG and charging handle not included) |
The Aero M5E1 is designed to work with standard AR .308 lower receivers. It accepts .308-pattern components and uses standard .2795" takedown pin holes, so you can pair it with any quality .308 lower that follows these specifications.
Yes, this upper arrives fully assembled. The barrel, gas block, gas tube, and flash hider are all installed and ready. You'll need to add your own bolt carrier group and charging handle before running it, but there's no gunsmithing required on the upper itself.
Yes. The handguard has a 1.78" internal diameter that accommodates most muzzle devices and 1.5" suppressors. The flash hider is a standard .308 A2 birdcage, which you can swap for other muzzle devices as needed.
Fluting removes material along the barrel's length, which reduces overall weight while maintaining rigidity and strength. On an 18" barrel, this helps lighten the rifle's front end without compromising accuracy or barrel performance.

SKU: 126797496 • Weight: 5.6oz
Availability: In Stock
Current Stock: Out of stock
The Aero Precision M5E1 complete upper 18" .308 stainless steel fluted receiver is a fully assembled platform built for shooters who want a battle-ready .308 AR without sourcing a dozen separate components. This upper comes ready to mate with your .308 lower—no BCG or charging handle needed—with a free-floated handguard, gas tube, flash hider, and gas block all installed and tuned. It's the kind of no-nonsense upper that works equally well for precision rifle duties at distance or duty-grade reliability on the range.
The receiver itself is forged from 7075-T6 aluminum and precision-machined to Aero's exacting standards. It features M4 feedramps, standard AR .308 component compatibility, forward assist and port door already installed, and quick-disconnect sling sockets at the 3, 6, and 9 o'clock positions on the handguard for flexible carry options. The Gen 2 Enhanced M-LOK handguard is machined from 6061-T6 aluminum with a 1.78" inside diameter that plays nicely with most muzzle devices and 1.5" suppressors, and it floats free for consistent barrel harmonic behavior.
The barrel is where things get serious: 18 inches of 416R stainless steel with a 1/10 twist, drilled for rifle-length gas and a .750 gas block journal. Fluting saves weight without sacrificing rigidity. The barrel is HP and MPI tested to Aero's standards, so you're getting proven metallurgy, not guesses. It ships with a standard .308 A2 birdcage flash hider installed, low-profile gas block compatible, and rifle-length gas tube ready to cycle your rounds reliably.
This is a complete upper for shooters who respect precision and reliability in equal measure—whether you're building a mid-range hunting rifle, a distance-shooting platform, or a duty-grade .308 AR that simply needs to work.
| Caliber | .308 Winchester |
| Barrel Length | 18" |
| Barrel Material | 416R Stainless Steel, fluted |
| Twist Rate | 1/10 |
| Gas System | Rifle length |
| Gas Block Journal | .750" |
| Receiver Material | 7075-T6 Aluminum |
| Receiver Type | M5E1 |
| Handguard | Gen 2 Enhanced M-LOK, 15", free-floated |
| Handguard Material | 6061-T6 Aluminum |
| Handguard Internal Diameter | 1.78" |
| Flash Hider | .308 A2 Birdcage |
| Included | Upper receiver, handguard, gas block, gas tube, flash hider (BCG and charging handle not included) |
The Aero M5E1 is designed to work with standard AR .308 lower receivers. It accepts .308-pattern components and uses standard .2795" takedown pin holes, so you can pair it with any quality .308 lower that follows these specifications.
Yes, this upper arrives fully assembled. The barrel, gas block, gas tube, and flash hider are all installed and ready. You'll need to add your own bolt carrier group and charging handle before running it, but there's no gunsmithing required on the upper itself.
Yes. The handguard has a 1.78" internal diameter that accommodates most muzzle devices and 1.5" suppressors. The flash hider is a standard .308 A2 birdcage, which you can swap for other muzzle devices as needed.
Fluting removes material along the barrel's length, which reduces overall weight while maintaining rigidity and strength. On an 18" barrel, this helps lighten the rifle's front end without compromising accuracy or barrel performance.
SKU: 126797496 • Weight: 5.6oz
