The Wilson Combat Bolt Carrier Assembly (brand part no. TRBCASBN556) is a 5.56 NATO, full-auto (M16) profile bolt carrier group with a 9310 tool steel bolt and an 8620 hardened steel carrier, finished in black nitride for reliable, durable performance. Wilson Combat builds it as a straightforward upgrade or replacement for any AR-15 shooter who wants a corrosion-resistant, low-friction finish over a standard phosphate carrier. The nitride treatment holds up to sustained fire while staying easier to clean than a traditional parkerized finish, making it a dependable choice for a duty, competition, or range rifle.

Key Specifications

• Chambered for 5.56 NATO / .223 Remington.
• Bolt is machined from 9310 tool steel for high-strength, fatigue-resistant performance.
• Carrier is machined from 8620 hardened steel.
• Built to a full-auto (M16) profile, which helps lower cyclic rate on short-barrel and suppressed builds.
• Ships with a properly staked gas key for reliable, long-term function.
• Finished in black nitride for corrosion resistance and easier cleaning.
• Built as a complete bolt carrier assembly for AR-15 uppers.
• Overall length measures approximately 10 inches.

Frequently Asked Questions

What finish does this carrier use? Black nitride over the 9310 steel bolt and 8620 steel carrier, for corrosion resistance and easier cleanup than a standard phosphate finish.

What caliber is it built for? 5.56 NATO, which also safely chambers .223 Remington.

Buy the Wilson Combat Bolt Carrier Assembly

A nitride-finished stainless carrier is a dependable, corrosion-resistant upgrade for any 5.56 AR-15 upper. Order it from Wilson Combat through our Lubbock, Texas gun shop for fast, direct shipping, and browse more AR bolt carrier groups to complete your build.