The AR15 receiver extension nut, also known as a castle nut, is what keeps the lock plate in place on adjustable stock kits for AR-15, M4, and AR-10 rifles. This sturdy steel castle nut works with Mil-spec military, commercial, and hybrid receiver extension buffer tubes on the AR-15 and AR-10 LR-308 carbines and pistols. It’s a rugged pick if you're looking to upgrade your rifle or need to replace old or damaged parts. This steel castle nut for sale has a limited lifetime warranty. It's virtually indestructible, is made in the USA, and features a sleek matte black finish.
The AR-15 steel castle nut upgrade is used to join the end plate and the buffer tube to the receiver. The steel castle nut keeps the buffer tube in place and resists the vibrations as the bolt moves back under tension from the buffer and spring. The castle nut is an essential part of an AR-15 platform. It is necessary for the proper and reliable performance of your AR platform rifle, pistol, or M4 carbine.
