43 Spanish Chamber

[Don McDowell]

I would guess you have a 43 Spanish chamber. A lot of those old guns have pretty inconsistent chambers, and bore dimensions. It'll probably shoot pretty well once you get the cases fire formed, resizing the cases most likely won't be necessary with a bullet correct for the bore. Probably going to have to order a bullet mould from Accurate to get one that will drop you a .441 diameter bullet, as I believe the Lyman bullet drops at .439.