The Angstadt Arms UDP-9 SBR with a B5 Bravo stock is a compact 9mm short-barreled rifle machined from 7075-T6 billet aluminum and built around Glock-pattern magazines (brand part no. AAUDP09S06). Angstadt Arms has fielded the UDP-9 since 2014, and the company says it is now in the hands of professionals and citizens in more than 30 countries. This rifle configuration pairs a B5 Systems Bravo stock and pistol grip with an Angstadt Arms EMT-9 trigger and a Radian Weapons Talon ambidextrous safety selector. Because it is compatible with most AR9 and AR15 parts, upgrades are straightforward, and the complete rifle is 22 inches long and under 5 pounds. It makes a handy home-defense carbine or a short, quick-handling host for range days.

Key Specifications

• Chambering is 9mm, an affordable, low-recoil cartridge for a short rifle.
• The action is straight blowback, a simple operating system well suited to a pistol-caliber carbine.
• The barrel is 6-inch chrome moly with a black Melonite finish and a 1:10 twist, a durable, corrosion-resistant setup for common 9mm loads.
• The muzzle is threaded 1/2×28 and fitted with an Angstadt Arms A2-style flash suppressor, so standard 9mm muzzle devices thread on.
• Both receivers are 7075-T6 billet aluminum, with a flared magwell and last-round bolt hold open on the lower.
• The handguard is a 5.5-inch Ultra Light M-LOK with a continuous 1913 top rail and slots at 3, 6 and 9 o’clock.
• Furniture is a B5 Systems Bravo rifle stock and pistol grip, giving a solid cheek weld on a short rifle.

Frequently Asked Questions

What magazines does it take? It accepts Glock aftermarket magazines, and one 17-round Glock magazine is included. Angstadt Arms recommends factory Glock magazines for best results.

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.

Can I swap in AR parts? Angstadt Arms says the UDP-9 is compatible with most AR9 and AR15 parts and components, and with most aftermarket 9mm PCC triggers.

Buy the Angstadt Arms UDP-9 SBR 9mm, 6-Inch Barrel, B5 Bravo Stock

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 Angstadt Arms‘s short barrel rifles lineup and our Lubbock, Texas team will handle the transfer, and it ships fast to your Class 3 dealer. Few 9mm rifles pack this much into 22 inches.