
Steampunk, no?
To shoot it you pull the gizmo on the back out to cock it then when you pull the trigger it pulls the striker (like a firing pin) back further then releases it. The round fires, the recoils cocks the striker and you can then pull the trigger again.
I will fire it but it is over a hundred years old and it makes me kinda nervous.
Here is the Wiki write up
https://en.wikipedia.org/wiki/Roth%E2%80%93Steyr_M1907
It fires the 8mm Roth-Steyr, a somewhat less than impressive round.
https://en.wikipedia.org/wiki/8mm_Roth%E2%80%93Steyr
After a cursory search it is not available as of today.
It is notable as being the first semi auto pistol accepted my a major military power (Austria 1907). The Luger was adopted by the Swiss in 1909 if memory serves.
This is my third Steyr pistol. They all have an alien look, perhaps because firearm evolution passed them by so they never attained the visual currency of a luger or m1911, both of which sorta defined the way pistols look. It might be thought of as the Trilobite of pistol evolution.