The Aero Precision M4E1 .223 Wylde assembled upper receiver with 16" barrel and mid-length gas system is a versatile, ready-to-build option for shooters who want precision rifle performance in a handy carbine format. Built from 7075 T6 forged aluminum and hard-coat anodized to mil-spec standards, this upper handles both 5.56 NATO and .223 Remington ammunition — including heavier target loads up to 80 grains — thanks to the .223 Wylde chamber. The mid-length gas tube on this 16" model is tuned to slow gas velocity for smoother cycling, less carrier tilt, and easier shooting without sacrificing reliability.

This is an assembled upper only: you'll need to source your own bolt carrier group and charging handle to complete the build, giving you full control over how your rifle feels and performs. The M4E1 platform accepts standard AR-15 mil-spec parts, so you're not locked into proprietary gear. The 416R stainless steel barrel features 1-8" rifling — a fast twist that stabilizes heavier projectiles — and arrives with an A2-style flash suppressor already installed. Ejection port cover and forward assist are included.

The Gen 2 Enhanced M-LOK handguard runs 15" in length with a continuous Picatinny top rail from receiver to front, eliminating the gap or seam you'll find on some competitors' designs. Inside diameter clears modern suppressors and muzzle devices up to 1.5" diameter, while the monolithic platform gives you rock-solid accessory mounting. Milled texturing on the handguard flats improves your purchase under recoil and adds visual character. This upper is a solid foundation for a hunting rifle, match build, or general-purpose 5.56 rifle.

The Aero Precision M4E1 .223 Wylde assembled upper receiver with 16" barrel and mid-length gas system is a versatile, ready-to-build option for shooters who want precision rifle performance in a handy carbine format. Built from 7075 T6 forged aluminum and hard-coat anodized to mil-spec standards, this upper handles both 5.56 NATO and .223 Remington ammunition — including heavier target loads up to 80 grains — thanks to the .223 Wylde chamber. The mid-length gas tube on this 16" model is tuned to slow gas velocity for smoother cycling, less carrier tilt, and easier shooting without sacrificing reliability.

This is an assembled upper only: you'll need to source your own bolt carrier group and charging handle to complete the build, giving you full control over how your rifle feels and performs. The M4E1 platform accepts standard AR-15 mil-spec parts, so you're not locked into proprietary gear. The 416R stainless steel barrel features 1-8" rifling — a fast twist that stabilizes heavier projectiles — and arrives with an A2-style flash suppressor already installed. Ejection port cover and forward assist are included.

The Gen 2 Enhanced M-LOK handguard runs 15" in length with a continuous Picatinny top rail from receiver to front, eliminating the gap or seam you'll find on some competitors' designs. Inside diameter clears modern suppressors and muzzle devices up to 1.5" diameter, while the monolithic platform gives you rock-solid accessory mounting. Milled texturing on the handguard flats improves your purchase under recoil and adds visual character. This upper is a solid foundation for a hunting rifle, match build, or general-purpose 5.56 rifle.