Spikes STU5025R9S Complete Upper 5.56x45mm NATO 16" Black Phosphate Barrel, 7075-T6 Aluminum Black Receiver, 9" BAR2 Free-Float Handguard for M4 Carbine

The Spikes STU5025R9S complete upper is a factory-inspected, ready-to-run upper receiver assembly built on a 7075-T6 aluminum forging and paired with a 16-inch 5.56x45mm NATO barrel in black phosphate. This is the core you need for a fast, accurate M4 carbine build—drop it onto your lower receiver and you're armed. Spikes assembles and test-fires every upper before it ships, so you're getting a vetted component, not a dice roll.

The 9-inch BAR2 free-float handguard decouples from the barrel, eliminating harmonics that can throw your shots off-target, while the M4 profile barrel strikes the balance most shooters want: light enough to handle all day, stiff enough to keep groups tight from 0 to 300 yards and beyond. The forged upper receiver meets military-spec tolerances, and the black phosphate finish on the barrel resists corrosion in field conditions without adding bulk.

Whether you're a competitive shooter, a hunter who values reliability over mall-ninja features, or someone building a rifle to last, this complete upper gives you quality craftsmanship and function without the hype. Install it, run it, trust it.

Key Features

• Forged 7075-T6 aluminum upper receiver, black anodized
• 16-inch 5.56x45mm NATO barrel, black phosphate finish, M4 profile
• 9-inch BAR2 free-float handguard for reduced harmonics and improved accuracy
• Factory test-fired and inspected before shipment
• M16 complete bolt carrier group included
• Compatible with standard M4 lower receivers

Specifications

Frequently Asked Questions

Will this complete upper work with my M4 lower receiver?

Yes. This Spikes complete upper is compatible with standard M4 lower receivers. Pair it with any mil-spec lower and you have a functional rifle.

Is the bolt carrier group included?

Yes. The STU5025R9S ships with an M16 complete bolt carrier group, so you have everything needed for the upper assembly to run.

What does the free-float handguard do?

The 9-inch BAR2 free-float handguard isolates the barrel from the upper receiver. This reduces vibration and harmonics during firing, which typically improves accuracy by letting the barrel shoot more consistently.

Has this upper been tested?

Yes. Spikes test-fires every complete upper before shipment to verify function and reliability.