UTG Pro Mil-Spec Receiver Extension Kit – AR-15, 6-Position

The UTG Pro Mil-Spec Receiver Extension Kit (brand part number TLU001KIT) is a complete buffer tube assembly built for AR-15 platform rifles. Machined from 6061-T6 aluminum with rolled threads and finished in matte black hard coat anodize, the 6-position extension tube is the mil-spec diameter that fits the widest range of aftermarket stocks. The kit includes everything needed to finish a lower build in one box: the carbine buffer, buffer spring, receiver end plate, and castle nut, all made in the USA. It’s a straightforward way to get a complete, correctly sized buffer system without sourcing four or five separate parts.

Key Specifications

• Machined from 6061-T6 aluminum with rolled threads.
• Finished in matte black hard coat anodize.
• Built as a 6-position extension tube in mil-spec diameter.
• Includes a carbine buffer and buffer spring.
• Includes a receiver end plate and castle nut.
• Made in the USA by UTG Pro.

Frequently Asked Questions

What’s included in this kit? A 6-position extension tube, carbine buffer, buffer spring, receiver end plate, and castle nut.

Is this a mil-spec or commercial diameter tube? Mil-spec diameter, fitting the widest range of aftermarket stocks.

What is the tube made from? 6061-T6 aluminum with rolled threads and a matte black hard coat anodized finish.

Buy the UTG Pro Mil-Spec Receiver Extension Kit – AR-15, 6-Position

Finish your lower build with one complete, correctly sized kit. Order it from our UTG Pro lineup, part of our rifle stocks selection, at our Lubbock, Texas gun shop for fast, direct shipping.