Revchopp, I also could be weak for a Cooper 52. This company is a full blowen custom shop which sold to the bench rest crowd. As far as caliber, if you reload I would either get a .280 or .270. Also you may want to consider selling one of your .270's if that is your choice, hard to do! I would suggest you make 2 different decisions. First, get what you really want and need, then decide if you have too many of one caliber. A .280 with reloads taylored to it can be just a little short of a 7mm mag. and very acurate. Maybe you could sell one of the .270's to help to pay for some premium glass to fit the new rifle. These are just suggestions, the only way to go is what feels right to you.
Buckfever