Aero Precision .308 Winchester Bolt Carrier Group

The Aero Precision .308 Winchester Bolt Carrier Group delivers the hardened steel construction and precision machining required for reliable large-frame AR operation, whether you’re building a battle rifle or a long-range precision platform.

What you get

• 8620 tool steel carrier with mil-spec phosphate finish
• 9310 steel bolt, case-hardened and MPI/HPT tested
• 4130 steel gas key secured with Grade 8 hardware and proper staking
• 8740 steel firing pin with hard chrome coating
• Forward assist serrations for positive engagement
• Laser-engraved Aero Precision logo

Build and finish

This isn’t a rebranded OEM part. Aero Precision’s .308 BCG starts with 8620 tool steel carriers that undergo stress-relieving heat treatment before machining. The bolt uses 9310 steel – a common alternative to C158 in large-frame applications – with proper case hardening for wear resistance. Both components receive magnetic particle and high-pressure testing to verify structural integrity.

The phosphate finish isn’t just cosmetic. This mil-spec coating retains lubricity better than bare steel during sustained fire. Gas key attachment follows military staking patterns using 4130 steel and Grade 8 fasteners, while the chrome-plated 8740 firing pin resists peening. Every dimension adheres to DPMS-pattern .308 specifications, including the cam pin path and carrier tail dimensions.

Compatible platforms

• DPMS-pattern AR-10 lowers
• Aero Precision M5 receivers
• Palmetto State Armory PA-10
• Armalite AR-10 (requires carrier modification)
• Most .308 Win/7.62x51mm large-frame builds

Installation notes

Drop-in installation requires no gunsmithing on compatible receivers. Apply a light coat of lubricant to the carrier rails and bolt lugs before initial use. Check gas key clearance with your upper receiver’s gas tube during assembly.

While we specialize in Glock components, we source this BCG directly from Rare Breed Triggers for builders who demand proven large-frame reliability. It’s the same attention to metallurgy and testing that goes into our select-fire components, applied to a platform that benefits from overbuilt parts.