I have a mid ‘90’s CRF Winchester M70 action.

It was originally chambered for 7mm STW.

Also on hand is a Sunny hill drop magazine
made for ultra mag rounds.

Is this action and magazine capable without
very excessive gunsmithing to accept and handle being made into a .510 Wells?

Thanks

well .. to answer your question
the bolt face would need to be opened from .532 to .580

consider a 500 accrel or 500mbogo . neither will require the bolt face to be opened

I respect all the various ‘50s cartridges
but have a personal desire for the .510 Wells
if it is reasonably possible.

cool -- it should work on a m70, though it will be 2 down, and feeding could be fun .. i would suggest asking, before the fact, if D'arcy Echols would take the feeding work