Aero Precision .308 Winchester Bolt Carrier Group

Aero Precision’s .308 Winchester Bolt Carrier Group delivers mil-spec reliability for large-frame AR builds, combining precision machining with MPI/HPT validation for duty-grade performance.

What you get

• 8620 tool steel carrier with phosphate finish
• 9310 steel bolt, shot peened and phosphate coated
• 4130 steel gas key secured with Grade 8 hardware
• 8740 steel firing pin with hard chrome coating
• Laser-engraved Aero Precision logo
• Forward assist serrations
• 4340 steel extractor

Build and finish

The carrier’s 8620 tool steel construction withstands sustained fire while the phosphate finish retains lubricity. Gas key staking follows mil-spec patterns, preventing loosening under recoil. Bolt components undergo shot peening to relieve stress concentrations, critical for .308 Winchester’s higher pressure curve.

Precision-machined extractor geometry ensures consistent cartridge engagement, while the chrome-plated firing pin resists corrosion. Unlike budget BCGs, this unit maintains headspace tolerances within 0.003″ for reliable ignition across temperature extremes.

Compatible platforms

• AR-10 pattern rifles (DPMS compatible)
• Large-frame AR builds using .308 Winchester/7.62 NATO
• Aero Precision M5 upper receivers
• Other mil-spec .308 platforms

Installation notes

Properly lubricate bearing surfaces before initial use. Check headspace when pairing with new barrels. This BCG ships dry with protective grease—clean thoroughly before installation.

For builders working on large-frame polymer lowers or hybrid builds, this bolt carrier group provides the mass needed for reliable cycling with adjustable gas systems. Its phosphate finish pairs well with aftermarket coatings when customizing your platform.