AeroPrecision167528080
M4E1 .300 Bo Assembl Uppr Rcvr M4 16'' Bbl Pistol-Length Blk$634.23
Availability: In Stock
Current Stock: Out of stock
The Aero Precision M4E1 .300 Blackout assembled upper receiver is a straightforward, quality-built upper for shooters and builders who want to dial in their own bolt carrier group and charging handle. Chambered in .300 Blackout and built around a 10-inch chrome moly barrel with a pistol-length gas system, this upper comes ready to integrate into your AR-15 platform—you just need to supply your own BCG and charging handle. The 9-inch handguard gives you solid real estate for grip and accessory mounting without weighing down a compact build, and the low-profile gas block keeps the profile clean. Black anodizing and USA manufacturing mean you're getting a platform built to last through range sessions, hunting trips, or whatever you're building toward.
This is an assembled upper, not a complete one, which actually works in your favor: you're not paying for components you might want to swap anyway. The .300 Blackout cartridge shines in short-barrel applications like this—delivering serious velocity and energy downrange while staying subsonic when loaded appropriately. Whether you're building a truck gun, a home-defense AR, or an integrally suppressed setup, starting with a solid upper like this gives you a foundation you can trust.
A few things to know: the standard A2 flash hider is included but is not pinned or welded to the barrel. If you're planning a rifle build (16 inches or longer overall length), you'll need to pin and weld the muzzle device per ATF regulations to hit that legal rifle length. As delivered, this upper is a blank canvas—bring your own BCG, charging handle, and lower to complete the build.
| Brand | Aero Precision |
| Model | M4E1 Assembled Upper Receiver |
| Caliber | .300 Blackout |
| Barrel Length | 10 inches |
| Barrel Material | Chrome moly |
| Gas System | Pistol length |
| Handguard Length | 9 inches |
| Handguard Type | M-LOK |
| Gas Block | Low-profile |
| Muzzle Device | Standard A2 flash hider (not pinned or welded) |
| Finish | Black anodized |
| Includes | Assembled upper receiver, barrel, handguard, gas block, muzzle device |
| Does Not Include | Bolt carrier group, charging handle, lower receiver |
| Country of Origin | USA |
This is an assembled upper receiver—you get the barrel, handguard, gas system, and muzzle device. You'll need to source a bolt carrier group, charging handle, and lower receiver to complete a functional rifle.
No. The A2 flash hider is removable as shipped. If you're building a rifle (16 inches or longer), you'll need to pin and weld the muzzle device yourself or have a gunsmith do it to meet ATF length requirements.
The .300 Blackout cartridge was designed for short barrels and delivers excellent velocity and energy even at lengths like 10 inches where many other rounds lose efficiency. It's also subsonic-capable with appropriate ammunition.
Yes, as long as your lower is a standard AR-15 platform receiver. This is a direct-fit assembled upper for any mil-spec or commercial-spec AR-15 lower.
SKU: 167529626 • Weight: 3.35oz
Availability: In Stock
Current Stock: Out of stock
The Aero Precision M4E1 .300 Blackout assembled upper receiver is a straightforward, quality-built upper for shooters and builders who want to dial in their own bolt carrier group and charging handle. Chambered in .300 Blackout and built around a 10-inch chrome moly barrel with a pistol-length gas system, this upper comes ready to integrate into your AR-15 platform—you just need to supply your own BCG and charging handle. The 9-inch handguard gives you solid real estate for grip and accessory mounting without weighing down a compact build, and the low-profile gas block keeps the profile clean. Black anodizing and USA manufacturing mean you're getting a platform built to last through range sessions, hunting trips, or whatever you're building toward.
This is an assembled upper, not a complete one, which actually works in your favor: you're not paying for components you might want to swap anyway. The .300 Blackout cartridge shines in short-barrel applications like this—delivering serious velocity and energy downrange while staying subsonic when loaded appropriately. Whether you're building a truck gun, a home-defense AR, or an integrally suppressed setup, starting with a solid upper like this gives you a foundation you can trust.
A few things to know: the standard A2 flash hider is included but is not pinned or welded to the barrel. If you're planning a rifle build (16 inches or longer overall length), you'll need to pin and weld the muzzle device per ATF regulations to hit that legal rifle length. As delivered, this upper is a blank canvas—bring your own BCG, charging handle, and lower to complete the build.
| Brand | Aero Precision |
| Model | M4E1 Assembled Upper Receiver |
| Caliber | .300 Blackout |
| Barrel Length | 10 inches |
| Barrel Material | Chrome moly |
| Gas System | Pistol length |
| Handguard Length | 9 inches |
| Handguard Type | M-LOK |
| Gas Block | Low-profile |
| Muzzle Device | Standard A2 flash hider (not pinned or welded) |
| Finish | Black anodized |
| Includes | Assembled upper receiver, barrel, handguard, gas block, muzzle device |
| Does Not Include | Bolt carrier group, charging handle, lower receiver |
| Country of Origin | USA |
This is an assembled upper receiver—you get the barrel, handguard, gas system, and muzzle device. You'll need to source a bolt carrier group, charging handle, and lower receiver to complete a functional rifle.
No. The A2 flash hider is removable as shipped. If you're building a rifle (16 inches or longer), you'll need to pin and weld the muzzle device yourself or have a gunsmith do it to meet ATF length requirements.
The .300 Blackout cartridge was designed for short barrels and delivers excellent velocity and energy even at lengths like 10 inches where many other rounds lose efficiency. It's also subsonic-capable with appropriate ammunition.
Yes, as long as your lower is a standard AR-15 platform receiver. This is a direct-fit assembled upper for any mil-spec or commercial-spec AR-15 lower.
SKU: 167529626 • Weight: 3.35oz