The launch of the Hydra Weaponry BMP-23 5.56x45mm semi-automatic bull-pup personal defense weapon, legally considered a pistol, marks the return of a 1970s classic: the BMP-23 is a modern version – manufactured using state-of-the-art CNC technology – of the "Bushmaster-Gwinn Arm Pistol", a bull-pup pistol introduced in 1972 by Gwinn Firearms Company (headed by Mack Gwinn Jr., currently at the head of Hydra Weaponry) and later manufactured by Bushmaster Firearms until 1990.

The Bushmaster-Gwinn Arm Pistol was a 5.56mm semi-automatic, civilian version of the experimental Colt IMP GUU-4/P prototype, chambered in .221 Fireball and tested in 1968 by the US Air Force as a potential personal defense weapon for air crews, with little to no luck. The Bushmaster-Gwinn Arm Pistol wasn't much more successful on the civilian markets back in its days, but modern manufacturing technology is expected to improve its overall quality and thus performance.

Based on an AK-type long-stroke gas piston, feeding through AR-15/M4 type magazines and featuring an 11.5" (29 cm) barrel on an overall length of barely 20 inches (50,8 cm), the BMP-23 features an AR-15 grip, integral iron sights, and a unique 40-degree swivel receiver design that allows it to switch from right to left-hand operation.

MSRP for the Hydra Weaponry BMP-23 bull-pup pistol is set at $2,349.99 in the United States.