Certainly looks like a lot of fun, but that bullet looks too heavy to me.

Appears the mould is casting considerably oversize as well, as the bullets are greatly sized down before being loaded into the cases. Check out the length of the top band on the loaded rounds, and that the raised band as-cast, is gone completely, which lengthens the amount of sized lead bullet above the case mouth. You can see a tiny line, where the top band's edge 'was' before sizing.

Fun gun,though. I've just got a feeling that mould nor the dies, of course, are not original to the rifle, but were assembled together just as we might, in order to shoot the rifle. Interesting old mould, too, must be a base pour.