Aero Precision M4E1 5.56 NATO Custom AR-15 – 16" Threaded Barrel, Stag Arms Upper, Free-Float M-LOK Handguard
This custom AR-15 pairs an Aero Precision M4E1 lower with a Stag Arms upper, creating a lightweight, feature-rich rifle chambered in 5.56 NATO. A free-floating Stag Arms M-LOK handguard, continuous Picatinny top rail, and threaded 16-inch barrel give shooters a versatile platform ready for accessories and suppressed use. The rifle retains Aero Precision’s enlarged trigger guard and flared magazine well for faster, gloves-on handling.
Condition
Overall Condition: Very good condition, showing only light, superficial signs of prior handling or use.
Bore Condition: Excellent – clean, mirror finish, no signs of wear.
Bore Rifling: Excellent – sharp lands and grooves.
Specific Condition Notes: Minor handling marks are present on external surfaces, but no functional wear is observed.
What’s Included
- Aero Precision M4E1/Stag Arms 5.56 NATO semi-automatic rifle
- (1) Mission First Tactical 30-round polymer magazine
This build starts with the forged Aero Precision M4E1 lower receiver, machined from 7075-T6 aluminum and finished in hard-coat anodized black. The design integrates an enlarged trigger guard and flared magazine well to speed reloads and improve control with gloved hands.
A Stag Arms upper receiver and 16-inch 5.56 NATO barrel complete the top end. The barrel is threaded 1/2-28 RH and capped with an A2 flash hider, offering compatibility with common muzzle devices and suppressors.
The free-float Stag Arms aluminum handguard uses the M-LOK mounting system along its length, includes a QD sling socket, and covers a low-profile gas block. A continuous Picatinny rail with laser-engraved T-marks runs end-to-end for secure optic and accessory placement.
The rifle operates on a direct-impingement system, retains a standard safety selector, and features a 6-position collapsible polymer stock providing a 10.25-inch length of pull. Hard-coat anodizing on both receivers delivers corrosion resistance and a uniform matte black finish.