The LBE Unlimited Mil-Spec AR-15 Buffer Tube Kit (brand part no. MILBUFKT-CG) gives AR-15 builders every part needed to finish a lower receiver’s buttstock assembly in one gray-finished package. LBE Unlimited is a US manufacturer of gun parts and accessories, and this kit pairs a six-position mil-spec diameter buffer tube with a carbine-length recoil spring, a standard carbine recoil buffer, a receiver end plate, and a castle nut — everything needed to mount a collapsible stock without sourcing five separate parts. It suits builders finishing a fresh AR-15 lower or replacing a worn buffer tube assembly on an existing rifle. Among AR buffer systems, this kit is a straightforward, complete starting point.

Key Specifications

• The buffer tube diameter is mil-spec, matching standard six-position collapsible stocks.
• Includes a carbine-length recoil spring sized for six-position tubes.
• Includes a standard carbine recoil buffer.
• Includes a receiver end plate for mounting a sling swivel or QD point.
• Includes a castle nut to lock the buffer tube to the receiver.
• The finish is gray.
• Manufactured in the USA by LBE Unlimited.

Frequently Asked Questions

Does this kit include a stock? No, this kit includes the buffer tube, spring, buffer, end plate, and castle nut only — a compatible six-position collapsible stock is sold separately.

Will this fit any AR-15 lower? Yes, the buffer tube is machined to mil-spec diameter, which fits the large majority of aftermarket AR-15 lowers and collapsible stocks designed around that standard.

Buy the LBE Unlimited Mil-Spec AR-15 Buffer Tube Kit

A complete, gray-finished buffer tube assembly that takes the guesswork out of finishing an AR-15 lower is exactly what this LBE Unlimited kit delivers. Order it from our Lubbock, Texas gun shop and we will get it to you as soon as it’s ready to ship.