I hate to agree with Jerry on this, for no reason other than the fact that I LOVE the 5R. But a smart suggestion IS a smart suggestion after all... for the money of a 5R, you can definitely refine your current rifle into something special.
I'm thinking that if you have any interest at all in reloading, you would see some of your biggest improvements there, aside from proper bedding, and a match barrel wouldn't hurt.
.....I AM slightly curious about how big of difference the .408 or .418 do for wind drift @1000+, with their insane BC's. But holy hell is that ever pricy.