AR-15 castle nuts are used to secure the buffer tube to the lower receiver on compatible AR-15 platforms, helping keep the stock or brace assembly properly installed and stable during use. They play an important role in maintaining the fit and function of the rear receiver setup during builds, repairs, and upgrades. Different castle nuts can vary in finish, staking surfaces, and compatibility depending on the rifle configuration. This category includes AR-15 castle nuts built for proper fit, dependable function, and practical everyday performance.
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JE Machine Tech AR-15 Mil-Spec Castle Nut Black
JE MACHINE TECHOUR PRICE: $3.99This mil-spec castle nut is designed to secure a compatible carbine buffer tube or receiver extension to an AR-15 lower receiver. It is suitable for new firearm builds, replacement projects, repairs,... -
ARMASPEC Self-Retention Aluminum Caste Nut
ARMASPECOUR PRICE: $26.99ARMASPEC SELF-RETENTION CASTE NUT The ARMASPEC ARM6521-ODG Self-Retention Caste Nut is designed for reliable attachment and secure fitment of stocks and forends on your firearm. Constructed from... -
Armaspec ARM6521-BLK Self-Retention Caste Nut for AR-15 and Rifles
ARMASPECOUR PRICE: $26.99ARMASPEC ARM6521-BLK SELF-RETENTION CASTE NUT/AL Armaspec ARM6521-BLK Self-Retention Caste Nut in Black Aluminum The Armaspec ARM6521-BLK is a high-quality self-retention caste nut designed for... -
Armaspec ARM6521-FDE Self-Retention Caste Nut for Firearms
ARMASPECOUR PRICE: $26.99ARMASPEC ARM6521-FDE SELF-RETENTION CASTE NUT/AL Armaspec ARM6521-FDE Self-Retention Caste Nut for Firearms The Armaspec ARM6521-FDE is a high-quality self-retention caste nut designed specifically... -
BATTLEARMS AR15/M16 Receiver Extension Castle Nut
Battle Arms DevelopmentOUR PRICE: $7.00AR15/M16 Receiver Extension Lock Nut Mil-spec. receiver extension lock nut (castle nut) for use on AR15 carbines with an adjustable stock. Perfect for your new build or as a direct replacement for...