Ar-15 5.56Mm Semi-Auto Bolt Carrier Group Black

The LMT Defense L7D3 is a mil-spec 5.56mm semi-auto bolt carrier group built for AR-15 rifles that demand reliability without compromise. If you're assembling a new rifle or upgrading from budget components, this BCG brings the same durability LMT has supplied to military and professional users for years. It cycles reliably whether you're running a bare muzzle or a suppressed setup, making it a versatile choice for hunters, competition shooters, and tactical enthusiasts who refuse to cut corners on core components.

LMT Defense manufactures the bolt carrier groups used in their complete automatic weapon systems—so the engineering that goes into a military-grade platform translates directly to this semi-auto version. You're getting battle-tested geometry and materials in a straightforward, proven design that plays well with standard AR-15 parts and builds.

Whether you're refreshing an older rifle or making sure your new build starts with solid internals, the L7D3 is the kind of part that works quietly in the background and lets you focus on shooting. No exotic coatings or marketing fluff—just a functional, durable bolt carrier group that handles both suppressed and unsuppressed fire with the same consistent performance.

Key Features

• Mil-spec design compatible with standard AR-15 builds and uppers
• Proven performance in both suppressed and unsuppressed applications
• Semi-auto configured for civilian use
• Manufactured by LMT Defense, supplier of military-grade components

Specifications

Frequently Asked Questions

Will this bolt carrier group work with my mil-spec AR-15 upper?

Yes. The L7D3 is designed to standard mil-spec dimensions and is compatible with mil-spec AR-15 uppers and lowers.

Can I use this BCG in a suppressed rifle?

Yes. LMT Defense states the L7D3 works reliably in both suppressed and unsuppressed configurations.

Is this the semi-auto or full-auto version?

This is the semi-auto L7D3. LMT Defense also makes a full-auto variant (L7A3) for those who are licensed, but this model is configured for civilian semi-automatic use.