Zeus Arms Proteus Pistol, 5.56 NATO/300 Blackout, QD Barrel, Black

The Zeus Arms Proteus pistol in 5.56 NATO and 300 Blackout with a quick-detach barrel system and black finish (brand part no. 670724648101) is a compact survival-style AR pistol built around a billet GHOST lower with the serial number engraved on the underside for a clean, customizable profile. Zeus Arms pairs a 7.5-inch 5.56 NATO barrel and an 8-inch 300 Blackout barrel, both nitride-finished 4150 CMV with a 1-in-7-inch twist, letting the shooter swap between calibers in seconds via the QD Cry Havoc barrel attachment. The build ships with an SB Tactical SBA3 side-folding brace for compact transport, a 30-round Lancer L5 Advanced Warfighter magazine, and a 7075-T6 M-LOK handguard, with a threaded 1/2-28 flash can included. Among AR pistols, the Proteus favors shooters who want a compact, multi-caliber survival platform.

Key Specifications

• Chambers both 5.56 NATO and 300 Blackout via swappable barrels.
• The 5.56 barrel measures 7.5 inches, and the 300 Blackout barrel measures 8 inches.
• Barrels use a quick-detach (QD) system for caliber changes in seconds.
• Barrel steel is nitride-finished 4150 CMV with a 1-in-7-inch twist.
• The brace is an SB Tactical SBA3, and it side-folds for compact storage.
• The lower receiver is billet, with the serial number engraved on the underside.
• The handguard is machined from 7075-T6 aluminum with M-LOK mounting points.
• Ships with a 30-round Lancer L5 Advanced Warfighter magazine.
• The muzzle device is a flash can threaded 1/2-28.

Frequently Asked Questions

Can this pistol switch between calibers? Yes, the QD barrel system lets the shooter swap between the 5.56 NATO and 300 Blackout barrels in seconds.

Does the brace fold? Yes, the SB Tactical SBA3 side-folds for compact transport in a backpack or pistol case.

What magazine does it ship with? A 30-round Lancer L5 Advanced Warfighter magazine.

Buy the Zeus Arms Proteus Pistol

A compact, multi-caliber survival pistol with a quick-swap barrel system is exactly what the Proteus delivers. Order it from our Lubbock, Texas gun shop for fast, insured shipping to your FFL.