Faxon Firearms 308/6.5 Creedmoor Gen 2 Bolt Carrier Group, Nitrided – FF308BCGCNITRIDE-02

Last reviewed: 2026-04-17 by Jake Terry, FFL07/SOT3, with hands-on install experience on AR/AK/Glock platforms.

The Faxon Firearms Gen 2 Bolt Carrier Group bridges the gap between mil-spec reliability and modern metallurgy for AR-10 and LR-308 builds. Chambered in .308 Winchester and 6.5 Creedmoor, this BCG uses 9310 tool steel for the bolt — a material choice that delivers higher tensile strength than traditional C158 — and applies QPQ salt bath nitride to the entire carrier and bolt assembly. The result: a surface hardness that resists wear, corrosion protection that outperforms chrome or manganese phosphate, and a low-friction finish that sheds fouling during high round-count sessions. At 17.9 oz, the Gen 2 BCG maintains full-auto fire rating and accommodates both legacy fire control groups and modern multi-stage triggers without modification.

The Mechanism

Faxon Firearms machines the bolt from 9310 tool steel, a nickel-chromium-molybdenum alloy known for superior fatigue resistance under cyclic loading. The carrier body uses mil-spec 8620 steel, and the extractor is 4140 tool steel. After assembly, the entire BCG undergoes QPQ salt bath nitriding — a thermochemical diffusion process that hardens the surface to 70 HRC while leaving the core ductile. Faxon Firearms then applies a proprietary Superfinish to further reduce friction coefficients and smooth the bearing surfaces. The gas key fasteners are grade eight hardware, fully staked per TDP requirements. Dual O-rings seal the bolt, and the unit ships with .308-spec springs installed. Magnetic particle inspection confirms structural integrity before the BCG leaves the facility.

Fit & Compatibility

This Gen 2 BCG fits DPMS-pattern AR-10 and LR-308 upper receivers. The carrier dimensions match mil-spec tolerances for drop-in installation with no fitting required. The bolt face, locking lugs, and extractor claw are machined to TDP geometry, ensuring compatibility with most .308 Winchester and 6.5 Creedmoor barrels. The full-auto carrier profile works with both semi-auto-only lowers and registered select-fire receivers, and the firing pin channel accommodates enhanced firing pins from major aftermarket suppliers. For builders seeking a direct replacement or an upgrade from chrome or phosphate BCGs, the Gen 2 integrates into existing bolt carrier group ecosystems without headspace adjustment in most cases.

Who It’s For

AR-10 builders running .308 Winchester or 6.5 Creedmoor who value corrosion resistance and low-friction operation over chrome finishes. Precision rifle competitors cycling high volumes during extended strings will appreciate the Superfinish treatment and nitride’s ability to shed carbon fouling. Hunters and designated marksmen operating in humid or marine environments benefit from the corrosion resistance of QPQ nitride, which outperforms traditional phosphate or chrome in salt-spray testing. The 9310 bolt steel suits high-round-count training schedules where fatigue life matters. If you’re assembling a new AR-10 or replacing a worn factory BCG, the Gen 2’s material choices and finish deliver measurable improvements in service life and maintenance intervals.