The 260 is a very forgiving round to reload, its accurate with almost any bullet. I've been using the 120 Nosler partition for a deer load and have recovered one bullet so far it was completely intact after passing end for end in a small local deer.
I would suggest you try a little of both, some rifles don't take well to the solid copper bullets, I have found in some cases the solid copper will foul a rough bore pretty quickly.