3D Animation: How a Derringer works 

I don't know the proper terminology, but the big and little catches on the rotary mechanism to enable top/bottom firing is pretty neat.

Nobody ever explains how the hinge lock works.

Does anyone know the name of the spring ?

I can't find a disassemble vid on Davis industries dm 22

Rimfire pistol rounds...

Sawed off: Pistol addition

Brilliant design for a small concealable pistol, made from 1866 to 1935 then copied by other manufacturers till today.

Btw is derringer made of copper nickel?