The CMMG Firing Pin (CMMG part no. 55BA41C) is a silver steel replacement pin built for AR-15 bolt carrier groups chambered in .223 Remington and 5.56 NATO. CMMG machines this pin to mil-spec dimensions, so it strikes the primer with the same reliable travel as the factory pin it replaces. Whether you’re replacing a pin that’s showing wear, building a new bolt carrier group from parts, or just keeping a spare on hand, this is a direct-fit component sized for the standard AR-15 platform. It’s a small part, but a worn or damaged firing pin is a common source of light strikes and failures to fire.

Key Specifications

• Machined from steel with a silver finish.
• Sized for .223 Remington/5.56 NATO AR-15 bolt carrier groups.
• Measures approximately 4.3 inches overall, matching mil-spec pin length.
• Strikes the primer when the hammer releases, igniting the chambered round.
• Built as a direct-fit replacement for the standard AR-15 bolt carrier group.
• Ships at 0.35 lb.

Frequently Asked Questions

What caliber is this firing pin for? It’s sized for .223 Remington/5.56 NATO AR-15 bolt carrier groups.

Will this fit a standard AR-15 BCG? Yes, it’s machined to mil-spec dimensions as a direct-fit replacement.

Buy the CMMG Firing Pin for AR-15

A worn or bent firing pin causes light strikes and failures to fire right when you can least afford them, and this CMMG pin is a cheap way to head that off. Order it from our CMMG lineup, part of our full selection of AR bolt carrier group parts, from our Lubbock, Texas gun shop.