If he has only 1/4" to get them in the chamber he is home free.
I am currently in the process of sizing cases for a coiled brass rifle. When I started the cases were sticking out of the chambers about 1 1/2". After several sizing dies (made by a machinist friend) I have about 1/4" to go. Work has pulled me away from this project so I haven't made any headway in about 6 weeks.
Someone may suggest rechambering to the 'modern' .450 BPE. Don't do it! The rifle has survived this long in original condition and once done there is no going back. Once you have 30-40 cases made up you will have a life time supply.
