Having served in the US Army Ordnance Corps I got to play with (and shoot) a lot of interesting weapons.

What I found most interesting was in my civilian days, a Mateba Semi-Auto Revolver. Yup, a self cocking revolver. Was in 44 Mag and surprisingly enough the recoil was well managed, both by the sliding mechanism but the upside down relationship of the barrel to standard revolvers. The barrel is located so the round at the bottom of the cylinder is the one fired.