The Arsenal AK-20 SASM7K SBR is a limited-edition custom shop AK in 7.62x39mm that rethinks the platform around a tunable gas system and a free-floating barrel (brand part no. SASM7K-85). It starts with a U.S.-manufactured milled receiver and all machined parts, then adds an 8.5-inch hammer forged, chrome-lined barrel that floats inside an aircraft-grade aluminum handguard. A 3-position gas system lets you run standard ammunition, subsonic ammunition when suppressed, or a restricted setting that softens bolt cycling. A free-floating Picatinny top rail runs the length of the receiver, and an AR-15 style telescoping stock replaces the traditional AK buttstock. It is built for the shooter who wants a modern short AK that is equally at home with or without a suppressor.

Key Specifications

• The chambering is 7.62x39mm, with subsonic loads supported by the gas system’s dedicated setting.
• Barrel length is 8.5 inches, free floating, hammer forged and chrome lined.
• Rifling twist is 1:9.44 (1 in 240mm) across four grooves.
• The muzzle has 24×1.5mm right-hand threads and the KR-009B 4-piece flash hider.
• The gas system is a 3-position tunable design with standard, subsonic and restricted settings.
• The top rail is a free-floating Picatinny rail 10.2 inches long with 25 slots, extending over the receiver for stable optics mounting.
• The handguard is aircraft-grade aluminum with a Magpul M-LOK lower section for lights, grips and other accessories.
• The stock is an AR-15 style telescoping stock, adjustable for length of pull and cheek weld.
• The metal finish is mil-spec black Cerakote, resisting wear, corrosion and chemicals.
• A 30-round mil-spec double stack M-47W magazine is included, and QD ports sit on both sides of the rear receiver.

Frequently Asked Questions

How does the AK-20 gas system work? Turn it to MIL-STD for standard ammunition or to SUB for subsonic ammunition when suppressed. The unmarked center setting restricts gas flow: with suppressed subsonic ammunition the shooter cycles rounds manually, and with suppressed supersonic ammunition it softens bolt cycling.

Do I need ATF approval to buy this? No. As of October 9, 2026, ATF no longer requires Form 4 approval, registration or a tax stamp for short-barreled rifles. It transfers on a Form 4473 with a background check through a Class 3 (SOT) dealer. State and local laws still apply. Taking an SBR across state lines still requires an approved ATF Form 5320.20.

Why is the barrel free floating? Arsenal configured the handguard, barrel and gas tube to minimize contact between parts, which improves heat resistance, stability and accuracy.

Buy the Arsenal AK-20 SASM7K SBR 7.62x39mm, 8.5-Inch Barrel

As of October 9, 2026, this short-barreled rifle transfers on a Form 4473 with a background check at your Class 3 (SOT) dealer, with no Form 4 or tax stamp; state and local laws still apply. Order through Arsenal‘s short barrel rifles lineup and our Lubbock, Texas team will handle the transfer, and it ships fast to your Class 3 dealer. Few short AKs are this ready for a suppressor straight from the factory.