Liegi derringer
I also own two of the liege typ derringers. my experience shooting it showed that it shoots a lot harder if i load it with a .464 ball. The ball gets pressed absolut tight into the barrel by beeing put on the powderchamber and screwing the barrel on. The barrelkey they supply is useless, instead I use a piece off bicycle tube to hold the barrel while screwing it on.As it takes quite a bit to force to get the barrel on one has to be carefull to hold the gun in a way that doing this does not break the little wooden handle(it`s pretty weak). Did enlarge the chamber that takes the powder a little bit,so now about 12 grains of fffg will fit, but I definately don`t recomend doing this .This little pistol shoots with very noticable recoil and the ball penetrates a lot more in pine than it does with the recommended ballsize. Biggest jump in power was because off the bigger ball. Funny gun laws here in Germany made me experimenting with these little derringers just for the case one day they make it impossible for me to own my legal modern guns.(single shot blackpowder pistols are free to own if you are over 18). To use an oversized ball was the actual reason for the invention of the screw barrel system. I unfortunately have a chrono to measure the fps but I figure it beeing now in the 550 fps range.Before anybody tries this he should check the bore size as these might vary(in my two guns they are the same)