Armaspec Self-Retention Castle Nut AR-15/M4 - Black Anodized Aluminum

The Armaspec Self-Retention Castle Nut is a purpose-built upgrade for AR-15 and M4 buffer tube assemblies. Machined from aluminum and finished in a hard black anodized coating, this castle nut features Armaspec's self-retention design that locks in place without the need for staking, giving a secure and rattle-free fit on any standard Mil-spec buffer tube.

Unlike a factory castle nut that must be staked or carefully torqued to keep it from backing off under recoil, the self-retention geometry grips the buffer tube threads and holds itself firmly in position. Installation is straightforward and tool-friendly, making it an easy drop-in upgrade for builders and shooters who want a low-maintenance, no-hassle stock retention solution.

Whether you are assembling a new build, replacing a worn factory nut, or simply want a cleaner and quieter buffer tube setup, the Armaspec Self-Retention Castle Nut delivers the durability and corrosion resistance expected from a quality AR platform component.