Just received an original #1 Rolling Block Rifle (Infantry Issue?) in 50-70 ( shootable condition)with some accessories....IE..Bayonet, loading set( Lyman 310) and a bullet mold. Also got 7 loaded rounds and 19 primed brass along with a piece of lead that shows rifeling marks. I assume the barrel has been slugged with this core of lead. My question is..That core mics at .506 across the widest marks, which should be the groves of the barrel. So what diameter bullet should be used in this rifle? I want to purchase bullets and shoot this thing before I acquire some raw lead and a pot. TIA2oraffs@starband.net