My MVP Varmint (24") never liked light bullets. Anything less than 62's it would make 6" groups with no matter what I did with the load recipe. I got the best performance from Berger 70gr VLD's and Hornady 75gr BTHPs and more recently from 73gr and 75gr ELD's. For powders, Varget, Benchmark, BL-C(2), IMR-4895 and similar medium burn rate powders did really well for me. For primers, I have never had good luck with non-magnum primers in .223's and usually use CCI #41's or Federal AR match or CCI #450s. I won't give out my charge weights because they're all massively over book. One tip, the MVP tends to have a long throat so skip mag-length loading, load long for .010 jump to get the powder capacity back, use that extra capacity and single feed them. I was able to get 70's and 75's to 2950fps that way though I would recommend working up slowly once you get near book max.
My factory MVP barrel was toasted pretty quickly due to me firing about 1000 rounds of copper washed steel jackets. That tore up the throat (and the rest of the barrel) pretty badly and ruined it as a target rifle (it did surprisingly well with the factory barrel) so I replaced the factory barrel with a 26" tube from Columbia River Arms in 1:7 twist. The rifling is polygonal instead of Enfield type so it doesn't engrave the bullet which doesn't abuse the jackets so bad allowing me to shoot really fragile and light weight bullets without jacket failures and I'm able to launch 80's with full stability.
