The 360 Precision 12.5″ Complete Upper is a fully assembled, ready-to-install AR-15 upper receiver group built on a billet 7075-T6 aluminum upper receiver with a 12.5-inch Criterion Core Series chrome-lined barrel in .223 Wylde. It ships with everything needed to drop onto any standard Mil-Spec AR-15 complete lower receiver and start shooting: barrel, BCG, charging handle, handguard, muzzle device, gas system, and dust cover.

The 12.5-inch barrel length makes this upper ideal for building a compact AR pistol or registered SBR. In .223 Wylde, the 12.5-inch barrel extracts meaningfully better velocity and terminal performance than shorter 10.3-inch or 11.5-inch configurations while keeping the overall package maneuverable for home defense, vehicle carry, and close-quarters use.

This is the same billet upper receiver and barrel quality found in the Recon CQB complete rifle, without the lower receiver and stock/brace components. If you already own a lower or want to build a custom configuration, this complete upper receiver gives you the 360 Precision barrel and receiver quality at a lower entry point.

Who should buy this complete upper?

• Builders who already own an AR-15 lower receiver and want to add a premium billet upper with a 12.5-inch Criterion Core Series chrome-lined barrel in .223 Wylde.
• Shooters building a compact AR pistol or SBR in .223 Wylde / 5.56 NATO who want 12.5 inches of barrel for improved ballistics over shorter alternatives.
• Anyone looking for the core components of a Recon CQB at a parts-level price point, with the flexibility to choose their own lower, brace/stock, and trigger.

What makes the Criterion barrel worth paying attention to?

The barrel is one of the most important component in a rifle, and this one uses a Criterion Core Series chrome-lined barrel. Criterion is one of a handful of barrel manufacturers whose name carries real weight with competitive and professional shooters. The Core Series is their production-grade line, built to tighter tolerances than most manufacturers’ barrels.

Chrome lining adds a hard chromium layer inside the bore that extends barrel life significantly, especially under high round counts and rapid-fire training schedules. A chrome-lined Criterion will hold accuracy longer than an unlined stainless barrel of the same quality under equivalent round counts. The trade-off historically was that chrome lining reduced peak accuracy compared to bare stainless. Criterion’s lining process has narrowed that gap to the point where most shooters cannot distinguish the two on paper.

This is the same barrel used in the Recon CQB Pistol. Buying the complete upper gives you the Recon CQB’s barrel, BCG, and billet receiver at a lower price, with the freedom to pair it with whatever lower and trigger setup you prefer.

How the 12.5-inch barrel length compares

If you are deciding between barrel lengths, here is how the three 360 Precision complete upper options compare:

12.5 inch (this upper): The compact option. Criterion CORE chrome-lined barrel. Carbine-length gas system. Best for AR pistol and SBR builds where maneuverability matters. The .223 Wylde chamber delivers better velocity and terminal ballistics than 10.3 or 11.5-inch barrels while staying compact enough for vehicle carry, home defense, and close-quarters use. Overall length depends on your lower’s brace or stock.

16 inch (also available): The full-length option. 416R stainless steel dimpled SPR barrel. Midlength gas system (smoother recoil impulse than carbine). Qualifies as a standard rifle without NFA considerations. Better velocity, more effective range, softer cycling. Best for general-purpose builds, range rifles, and builds where compactness is not the priority.

Both barrel lengths are available in Cerakote and anodized finishes. Both use the same billet 7075-T6 upper receiver, DLC-coated BCG, and M-LOK handguard. The barrels are the primary difference: Criterion chrome-lined at 12.5 inches vs. 416R stainless dimpled at 16 inches.

What you need to pair with this upper

Already own a complete lower receiver? Drop this upper onto it. If your lower has a trigger, grip, buffer assembly, and stock or brace installed, you are ready to shoot.

Need a complete lower? Our complete lower receiver ships with everything installed. Pair it with this upper for a functioning rifle in two pieces.

Starting from scratch? A stripped HD15 Gen2 lower plus your choice of trigger, grip, buffer, and stock. The HD15 Gen2’s integrated tension screw pairs with this billet upper for a zero-wobble fit.

You will also need an optic, magazine, and ammunition.

What’s included?

• Billet 7075-T6 upper receiver (slick side or forward assist)
• 12.5-inch Criterion Core Series chrome-lined barrel in .223 Wylde
• M-16 bolt carrier group with DLC coating
• Ambidextrous charging handle
• M-LOK handguard with Picatinny rail (6061 extruded aluminum) with Case Hardened QD Cups
• 360 Precision Vector-3 muzzle brake
• Melonite gas tube and low-profile gas block
• Custom Cerakote finish (single color, applied in-house)