Lovely rifles Buckstix!
Yes I prefer the P14/M17 Enfield for the 'bigger' capacity cartridges like Rule303!
The 425WR could be made out of 404J brass - albeit without the rebated rim, Jack Lott actually suggested this by having a second bolt opened up for the Jeffery brass!
It would be a more easily adaptable proposition & be a lower pressure cartridge than the 300WM case, providing you can get the Jeffery brass easier - well in my opinion anyway!
Mind you the 425 Express is no slouch & I'm splitting hairs here