Watch: Semi-Auto “Mystery Pistol” on Forgotten Weapons

Rock Island Auctions simply called this gun “Unknown Semi-Automatic” in the auction listing, and later a “unique prototype semi-automatic pistol.” Ian of Forgotten Weapons calls it a “rocking block mystery pistol.”

Chambered for 32 ACP, this little unmarked pistol may very well be one of a kind.

The breech block is pulled/held forward by a strong action spring that’s contained below the barrel. Two legs extend from the breech block downward into the grip of the frame, straddling the magazine, and lie in notches there. To operate the action, the breech block rocks rearward on those legs, which reveals the rear of the chamber and shoves the hammer backwards.

It would probably cock the hammer if the hammer was working properly. Alas, it is not. But even at that, it is interesting because it is apparently sprung by means of a spiral-wound flat spring (think of clock springs, or the recoil starter on a lawnmower or other small engine).

This method of propelling the hammer seems utterly inefficient to me; no wonder it’s not working.

But it’s still a neat old gun.

Russ Chastain

Editor & Contributing Writer Russ Chastain is a lifelong hunter and shooter who has spent his life learning about hunting, shooting, guns, ammunition, gunsmithing, reloading, and bullet casting. He started toting his own gun in the woods at age nine and he's pursued deer with rifles since 1982, so his hunting knowledge has been growing for more than three and a half decades. His desire and ability to share this knowledge with others has also grown, and Russ has been professionally writing and editing original hunting & shooting content since 1998. Russ Chastain has a passion for sharing accurate, honest, interesting hunting & shooting knowledge and stories with people of all skill levels.