At a garage sale today I found and purchased a percussion pistol, marked NORBERTO ARIZMENDI EIBAR MADE IN SPAIN. Barrel about 9-3/8 inches. Also marked 12 m/m. Appears unfired; the nipple has very slight peening from dry firing. Lots of rust in the barrel but seems to be a smoothbore, and the rust came out easily. I figured I did quite well for $25.00!! Any suggestions for ball size to try with this, Im thinking .45 PRB. Beginning load suggestions would be appreciated, also nipple size. Currently I shoot a .54 Hawken style flinter and a .45 CVA percussion rifle, so I have some vague ideas about what to expect. Thanks to all! Tom