use 308 classic loader on 7mm with 7mm neck die?

[CamaroMan]

wondering if I can modify a 308 classic lee loader to work on a 7mm RM - can turn basic parts on lathe but wondering if i can substitute the 7mm neck die? such a basic little kit dunno why they dont make it for the 7mm..

Also - measured a spent case - exactly 2.500", possible to not have deformation on magnum rifles? quite surprised..