I sent the pictures to a gunsmith who specializes in RB, and he said it is a New York State 50-70 or a Navy 50-45. It is definitely a black powder model from the firing pin. It has the decocking system when the breech is opened. The present barrel was from an '03 according to a local gunsmith. I will have to look for the cast of the chamber, but if I remember right it was Mauser dimensions, but 30 cal. I tried to make the brass from a .444 and actually fired it once. The fired round measured out to a 7.62x57, but this was a year or more ago, so I may not remember correctly. The cartridge would not eject, so I got discouraged and I went on to other projects. Now I want to play with this again. Maybe the extractor could be altered? If it would extract the shell, I would have no problem making brass and shooting cast bullets in it. It sure would be cheaper than rebarreling.