Leapers Inc. UTG Pro AR15 S4 Mil-Spec Stock Kit, FDE

The Leapers Inc. UTG Pro AR15 S4 Mil-Spec Stock Kit in FDE is a complete replacement stock assembly built for shooters who need a compact, rugged platform that works in real-world conditions. This mil-spec stock kit arrives with everything you need—extension tube, buffer, buffer spring, receiver end plate, and castle nut—so you can swap out an existing stock or complete a build without hunting down individual components. The FDE finish pairs durability with a professional look that works for duty, training, or tactical use.

The 4.28" length and 4-position adjustability let you dial in a comfortable length of pull whether you're running the rifle stripped down or wearing a plate carrier and load-bearing gear. That compact footprint matters in vehicles, tight spaces, or when you're geared up and need the gun to shoulder naturally without extending past your body. Built from impact-resistant polymer with tight tolerance controls, this stock is engineered for the hard use that comes with duty cycles and field conditions—not just bench shooting.

UTG's mil-spec design means it will work with any mil-spec AR-15 platform and plays well with standard parts ecosystems. If you're upgrading an existing AR or want a no-compromise stock for a new build, this kit removes the guesswork and gets you shooting faster.

Key Features

• Complete mil-spec stock kit—tube, buffer, spring, end plate, and castle nut included
• 4-position adjustability for length-of-pull customization
• Compact 4.28" length designed for plate carriers and load-bearing gear
• Impact-resistant polymer construction rated for heavy-duty use
• Flat dark earth (FDE) finish
• Tight tolerance controls for secure, rattle-free fit

Specifications

Frequently Asked Questions

Will this stock kit work on any AR-15?

Yes, this is a mil-spec stock kit designed to fit any AR-15 platform that accepts mil-spec components. It includes the extension tube, buffer, and spring you need for a complete installation.

Can I use this stock if I wear a plate carrier or body armor?

Absolutely. The compact 4.28" length and 4-position adjustability are specifically designed to give you a comfortable length of pull even when you're wearing tactical gear or a load-bearing vest, so the gun shoulders naturally without extension.

What comes in the box?

The kit includes the stock, mil-spec extension tube, buffer, buffer spring, receiver end plate, and castle nut—everything required for installation on a mil-spec AR-15 lower receiver.

Is the FDE finish durable?

Yes. The polymer is impact-resistant and matte, designed to handle heavy use in field conditions without degrading or showing wear easily. The tight tolerance manufacturing means minimal rattle and maximum reliability over time.