I’m sure I’m not the first with this idea but I was thinking can a person buy a 45/70 Ruger #1 and have it re-chambered to a 45-120 (.45 3 1/4) and then load it to the same level as a Rigby .450 3 1/4 N.E.
According to Guns and Ammo “Big Bore Rifles” by Jack Lott the .450 3 1/4 N.E. fired a 480gr R.N. bullet over 70gr Cordite with an ~MV of 2150fps. The closest data I can find is Hodgdon, which lists the 45-120 with a 500gr bullet at 1809fps. Hodgdon lists a 485gr load for the 45/70 but not the 45-120. Is this possible and does any one have smokeless data for the 45-120 and the .450 3 1/4 N.E.