I have quite a few 55 grain bullets. I know I could try them and see if they shoot accurately.
It depends upon what you mean by "best". There's no reason the 55 grainers won't shoot just fine from an 8 twist, I've shot a gazillion 55 grainers out of my two 8 twist 22-250's. The heavier bullets will buck the wind better and give better long range performance but there's no reason to think they'll shoot any more accurately than the 55's. Overstabilization is a myth.
But bullet integrity is not. There are many thin jacketed 55 grain bullets that could deform due to being spun too fast and loose accuracy. Of course there are certain bullets that take being spun hard without issues.
I guess the op can try them and see how they do. I don't know why he asks what people think are the "best", but then says he has a barrel full of 55's. I don't shoot 55's in anything, but that is just me. The lightest match bullet I'd sling in that rifle is the 69 SMK. Next step up would be the 73 ELD match and then the 77 TMK or SMK.. If none of those shot ragged hole groups, I'd be a little concerned.
