The Berlin-Suhler Waffenwerk (BSW) prototype pistol just never caught on.
This gas-operated pistol competed against the Walther P38 as the new German Army pistol.
Watch a demo of this extremely rare pistol.
The Berlin-Suhler Waffenwerk company submitted a gas-accelerated blowback design prototype pistol in 1936. It had an aluminum frame, 9mm chamber, stamped slide, and a 13-round magazine. It also had a double-action-only shrouded-hammer firing mechanism. The company only manufactured a small batch for testing.
Only three surviving specimens of this pistol are known to exist. This lucky shooter got to test one and examine it in detail.
The BSW prototype pistol competed against the Walther P38 in German Army field trials and lost. The ergonomics, heavy recoil, difficult disassembly, and large size doomed this pistol to failure.