The Armaspec Carbine Buffer Tube Kit with End Plate and Castle Nut (brand part no. ARM621-C) provides the core hardware needed to mount a collapsible stock onto an AR-15 lower receiver. Armaspec, founded in 2013, builds firearm accessories for the AR, Glock, AK, 1911, and other platforms, with a product line spanning magwell grips, charging handles, parts kits, selectors, stocks, and recoil systems. This kit covers the buffer tube along with the end plate and castle nut needed to secure it to the receiver, giving a builder the core hardware to complete a stock installation. It is a straightforward, no-frills option for anyone building or repairing the buffer tube assembly on a carbine-length AR-15.

Key Specifications

• Sized for carbine-length AR-15 buffer tube applications.
• Includes an end plate and castle nut, the hardware needed to secure the buffer tube to the receiver.
• Classified as a buffer tube component, sold to complete or replace a stock mounting system.

Frequently Asked Questions

What does this kit include? A carbine-length buffer tube along with the end plate and castle nut needed to mount it to an AR-15 lower receiver.

Does this include a stock or buffer weight? No, this kit covers the buffer tube and mounting hardware only; a stock and buffer/spring are sold separately.

Buy the Armaspec Carbine Buffer Tube Kit

Get the core hardware needed to mount a collapsible stock on an AR-15 build without hunting down each part separately. Browse Schaefer Defense’s AR buffer system parts and order from our Lubbock, Texas gun shop for fast shipping.