Complete AR-15 rifle build kits chambered in .223/5.56 — the most common AR-15 caliber. Each kit gathers a barreled 16″ upper assembly, handguard, bolt carrier group, charging handle, gas system, buffer tube, stock, grip, and lower parts kit. Kits ship with an 80% lower or without a lower, and assembled with mil-spec parts. They do not include a magazine or sights. Use the filters to sort by handguard, finish, and configuration.

AR-15 .223/5.56 Rifle Build Kits

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Choosing a .223/5.56 Build Kit

These kits are built around the .223/5.56 round, so they're the simplest path to a general-purpose AR-15. A few things to check before ordering.

With or without an 80% lower

"With 80% lower" kits include an unfinished 80% lower so you have everything and finish the lower yourself. "No lower" kits include everything except the lower — pick those if you already have one. The product title says which.

What's in the kit

A barreled upper (4150 chrome-moly barrel, M4 feed ramps, free-float Keymod or M-LOK handguard, muzzle device, BCG, charging handle, gas block and tube), plus a buffer tube, stock, grip, and lower parts kit. No magazine and no sights — add your own. Exact contents vary by kit; check the listing.

Why .223/5.56

.223 Remington and 5.56 NATO are the standard AR-15 chamberings — affordable, widely available, and versatile for target shooting, training, and general use. Most kits use a 16" barrel in a 1:7 or 1:8 twist, which stabilizes the common 55–77gr bullet weights.

Frequently Asked Questions

Do these kits include a magazine or sights?

No. The kit is the rifle's major components only — no magazine and no iron sights or optic. Add the magazine and sighting system you prefer.

What's the difference between "with lower" and "no lower" kits?

"With 80% lower" includes an unfinished lower receiver; "no lower" includes everything except the lower. Choose based on whether you already have a lower.

 Can I shoot both .223 and 5.56?

A 5.56-marked chamber safely fires both .223 Remington and 5.56 NATO. Confirm the chamber marking on the product page if you plan to shoot 5.56.

 Do you need an FFL to buy a rifle build kit?

It depends on how a kit is configured and where you live, and the rules around unfinished receivers and kits continue to evolve. Confirm current federal and state requirements and how a specific kit ships before ordering. This is general information, not legal advice.