Davidson Defense Agamemnon 16-inch Pistol-Gas 1:8 .300 Blackout AR-15 Freefloat Picatinny & M-Lok Handguard Rifle Complete Upper Build

Agamemnon 16-inch .300 Blackout AR-15 Complete Upper

The Agamemnon is built around a 16-inch .300 Blackout barrel with an HBAR profile, paired with a 7075-T6 aluminum upper receiver finished in black anodizing. It pairs a 15-inch Unique-ARs Slim Molon Labe handguard with a GI birdcage flash hider at the muzzle, running on a pistol-length gas system. A complete bolt carrier group and Mil-Spec charging handle round out the upper, giving the buyer everything needed on the upper side.

Key Features

• 16-inch .300 Blackout barrel, 1:8 twist, Phosphate finish
• Pistol-length gas system with micro low-profile steel gas block
• 7075-T6 aluminum upper receiver, black anodized finish
• Unique-ARs Slim Molon Labe 15-inch handguard with Molon Labe cutout pattern
• GI birdcage flash hider, compatible with .300 Blackout, .308 Winchester, and 7.62x39
• Complete bolt carrier group and Mil-Spec charging handle included

Barrel and Gas System

The barrel runs 16 inches long, chambered in .300 Blackout and finished in phosphate with an HBAR profile. It carries a 1:8 twist rate suited to that chambering and a 5/8x24 muzzle thread. Gas cycles back to the action through a pistol-length system rather than the carbine or mid-length setup more common on a 16-inch barrel, running a pistol-length gas tube and a micro low-profile steel gas block sized to a .750-inch journal.

Upper Receiver and Handguard

The upper receiver is machined from 7075-T6 aluminum and finished in black anodizing, cut with M4 feed ramps for smooth feeding and fitted with a standard AR-15 forward assist assembly. The ejection port carries a standard .223/5.56 door with its rod and spring installed. Over the barrel sits a 15-inch Unique-ARs Slim Molon Labe handguard finished in black, featuring a slim profile with a Molon Labe cutout pattern along its length.

Muzzle Device

Capping the muzzle is a GI birdcage flash hider, compatible with .300 Blackout, .308 Winchester, and 7.62x39. It threads onto the barrel's 5/8x24 pattern and is secured in its final timed position with a 5/8-inch black crush washer.

Bolt Carrier Group and Charging Handle

A complete AR-15 bolt carrier group is included, made in the USA and listed for use across 5.56 NATO, .223 Remington, .300 Blackout, and .350 Legend. That broader listing describes the BCG itself; the barrel and chambering on this upper remain .300 Blackout. A Mil-Spec AR-15 M4 charging handle rounds out the upper's operating components.

Follow all manufacturer instructions and safe handling practices.

Ensure compliance with all applicable federal, state, and local laws.