The Auto-Ordnance Thompson 1927A-1 SBR detachable stock model is a .45 ACP short-barreled rifle with a removable walnut buttstock (brand part no. T1BSB). It fires semi-automatic from a closed bolt through a finned 10.5-inch barrel, and the frame and receiver are machined from solid steel with a blued finish. A vertical foregrip gives it the profile most people picture when they think of a Tommy gun. Pulling the buttstock shortens the rifle from 35 inches to 25.5 inches, a real help for storage and transport. It ships with one 20-round stick magazine and suits the Thompson collector who wants the takedown-stock version.

Key Specifications

• The stock is a walnut detachable buttstock, which comes off for storage and transport.
• Overall length is 35 inches with the stock and 25.5 inches without, the figures Auto-Ordnance lists.
• The chambering is .45 ACP, the cartridge the original Thompson was designed for.
• The barrel is 10.5 inches and finned, the short barrel that defines this as an SBR.
• The action is semi-automatic from a closed bolt, firing one round per trigger pull.
• The frame and receiver are machined from solid steel with a blued finish, built like the original.
• The foregrip is vertical, the classic Tommy gun profile.
• Weight is 12 pounds, heavy for the size and steady on target.
• Sights are a blade front and open adjustable rear, simple and rugged.
• It ships with one 20-round stick magazine, the standard Thompson stick.

Frequently Asked Questions

How is this different from the other Thompson SBRs? This model has the walnut detachable buttstock and a vertical foregrip, and it ships with one 20-round stick magazine. Other Thompson SBRs use a fixed stock.

Does it have a compensator? Yes. Auto-Ordnance lists the finned barrel at 10.5 inches, or 12.5 inches with the compensator.

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.

Buy the Auto-Ordnance Thompson 1927A-1 SBR with Detachable 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 Kahr Arms‘s short-barreled rifles lineup and our Lubbock, Texas team will handle the transfer, and it ships fast to your Class 3 dealer.