CMMG Mk4 Receiver Extension Castle Nut Black Matte

The CMMG Receiver Extension Nut Mk4 is a castle nut designed for the receiver extension, also called the buffer tube, on an AR-15 platform rifle. It secures the buffer tube to the receiver and is used when assembling or replacing the receiver extension on a CMMG Mk4 AR-15.

This nut is offered in a black matte finish. The raw listing describes the component as made to strict military specifications, but no dimensional or material specifications are provided in the source data.

The part is listed for fitment to the CMMG Mk4 AR-15 receiver extension and is suited to upgrading existing components or replacing a worn or broken nut.

• Brand: CMMG
• Model: Receiver Extension Nut Mk4
• Type: Buffer Tube
• Platform: AR-15
• Fits: CMMG Mk4 AR-15 receiver extension
• Color: Black
• Finish: Matte