Aero Precision X15 M4E1 Gen 2 ATLAS R-ONE 5.56 NATO Semi-Auto Rifle, 16-Inch Barrel, 30+1
The Aero Precision X15 M4E1 Gen 2 pairs a forged 7075-T6 receiver set with the lightweight ATLAS R-ONE free-float handguard, giving shooters a durable yet streamlined AR-15 platform. This factory-built rifle comes in 5.56 NATO, features a 16-inch threaded barrel, and includes Aero’s enhanced upper with an integral handguard interface for added rigidity. Hard-coat anodizing to MIL-A-8625 Type III Class 2 ensures a tough, uniform matte-black finish.
Condition
Overall Condition: As-new condition with no signs of prior handling beyond what’s typical from inspection.
Bore Condition: Excellent – Clean, mirror finish, no signs of wear.
Bore Rifling: Excellent Rifling – Sharp lands and grooves.
Specific Condition Notes: Only minimal handling marks are visible upon close inspection.
What’s Included
- Aero Precision X15 M4E1 Gen 2 ATLAS R-ONE rifle
- One 30-round polymer windowed magazine
- Installed polymer M-LOK vertical foregrip
Designed around Aero Precision’s enhanced-forging upper, the rifle integrates the handguard mounting surface directly into the receiver. This eliminates a separate barrel nut interface and delivers a more rigid, monolithic feel without adding weight.
The 15-inch ATLAS R-ONE handguard uses a patent-pending two-bar clamp for secure, evenly distributed tension. Full-length numbered Picatinny slots run along the top, while M-LOK slots on the sides and bottom give plenty of space for lights, bipods, or other accessories.
The X15 Gen 2 lower includes a nylon-tipped tension screw to dial out receiver play and a threaded takedown-spring channel for easier maintenance. An adjustable telescoping stock and A2 grip provide a familiar control layout with an 11-inch length of pull.
The 16-inch barrel features 1/2-28 UNEF threads, ready for muzzle devices or suppressor mounts common to the 5.56 NATO platform. A direct-impingement system keeps the operating group lightweight and compatible with standard AR-15 components.