Troy A4 Complete Upper 5.56 NATO 16″

Product Description

The Troy A4 Complete Upper 5.56 NATO 16″ is a drop-in upper receiver assembly chambered in 5.56 NATO with a 16-inch barrel. It ships as a complete unit, ready to mate with any mil-spec lower receiver.

This upper is built for shooters who want a reliable carbine-length platform without piecing together individual components. The A4 designation refers to the flat-top receiver design that accepts optics and backup irons on a continuous Picatinny rail.

Because it arrives assembled, you skip headspace checking and barrel installation. Attach it to your stripped or complete lower, function-check, and head to the range.

Key Facts

• SKU: TRYSUPG-A4S-16BT-00
• Caliber: 5.56 NATO
• Barrel length: 16 inches
• Configuration: Complete upper assembly

What You Need to Complete the Build

A complete upper like the Troy A4 requires a compatible AR-15 lower receiver to function. The lower houses the fire control group, buffer system, and stock. If you already own a stripped or complete lower, this upper snaps on with the two takedown pins that bridge the receiver halves.

If you are starting from scratch, you will also need a bolt carrier group and charging handle unless they are included with this upper. Call 817-393-4000 to confirm exactly what ships with this assembly before you order.

Why Shooters Choose a 16-Inch 5.56 Upper

A 16-inch barrel is the shortest you can run on a rifle without entering NFA short-barreled rifle territory. It delivers better velocity than pistol-length barrels while keeping the overall package maneuverable for home defense, three-gun, and general-purpose use.

The 5.56 NATO chamber accepts both 5.56 military ammunition and commercial .223 Remington rounds. This flexibility matters when ammunition supply shifts or when you reload for precision work at the range.

Flat-top A4 uppers give you a full-length rail for mounting optics, magnifiers, and backup sights anywhere along the receiver. You are not locked into a carry-handle sight picture the way you are with an A2 upper.

Buying from Western Sport in Roanoke, TX

Western Sport is a licensed FFL/SOT dealer serving the North Texas and DFW area since 2007. Owner and gunsmith Lance Rankin and his team handle transfers, custom builds, and gunsmithing on site. Call 817-393-4000 to confirm specifications, place an order, or ask about pairing this upper with one of our complete AR uppers or other products in our online shop.

Frequently Asked Questions

Q: Will the Troy A4 complete upper fit my lower receiver?

A: The Troy A4 upper fits any mil-spec AR-15 lower receiver. Both forged and billet lowers that follow the TDP dimensional standard will mate correctly with this upper using standard takedown and pivot pins.

Q: Does this upper come with a bolt carrier group and charging handle?

A: Call 817-393-4000 to confirm what is included with this specific upper assembly. Some complete uppers ship with the BCG and charging handle installed; others require you to source those separately.

Q: Can I shoot .223 Remington through a 5.56 NATO chamber?

A: Yes. A 5.56 NATO chamber accepts both 5.56 military rounds and .223 Remington ammunition safely. The 5.56 chamber has slightly longer headspace dimensions to handle higher-pressure military loads.

Q: What is the difference between an A4 upper and an A2 upper?

A: An A4 upper has a flat-top Picatinny rail receiver that lets you mount any optic or iron sight you choose. An A2 upper has a fixed carry handle with integrated rear sight, limiting your optics options to side mounts or removing the handle entirely.

Q: How do I transfer an AR upper in Texas?

A: Upper receivers are not firearms under federal law and do not require an FFL transfer in Texas. You can order this upper online or by phone and have it shipped directly to your address, or pick it up at our Roanoke location.

Q: Is the Troy A4 upper covered by a warranty?

A: Contact Troy Industries directly or call Western Sport at 817-393-4000 to confirm current warranty terms for this upper assembly. Warranty coverage varies by manufacturer and product line.

Additional information