Description
The Luth-AR Carbine Lock Ring / Castle Nut is a precision-machined threaded steel ring designed to securely retain the carbine buffer tube to the lower receiver on AR-15, AR-10, and M16 platforms. Manufactured from tough 4140 steel with a manganese phosphate finish, this essential component provides reliable locking strength and corrosion resistance for your collapsible stock assembly.
A direct mil-spec replacement or upgrade part, it installs easily with standard tools and ensures your buffer tube stays firmly in place under heavy recoil and extended use.
Features
- Threaded steel castle nut for secure buffer tube retention
- Made from durable 4140 steel
- Manganese phosphate finish for corrosion resistance and durability
- Precision machined for perfect fit on mil-spec carbine buffer tubes
- Compatible with all standard AR-15, AR-10, and M16 carbine stocks
- Essential component for proper stock assembly and stability
- Proudly made in the USA by Luth-AR









