RE: Browning BOSS
If you handload, they might not be worth the trouble. My M70 .300 stainless WinMag shoots great with only one slug (Sierra Pro Hunters, 1 MOA all the way to 600 yards), but I went through a boatload of ammo to get there. None of the "premium" bullets worked.
I installed the CR version to lessen hearing damage in the field, and I'm glad I did.
When it wears out (3,000 shots and still shoots great) I'll probably just replace it with a custom barrel. I'll get 2" more barrel and should be able to find a load that woeks just as well.