I'm looking to load my mark2 m77 with hornady 154 sst. I've tried several combinations with IMR 4831, IMR 4350 and RL 25 and my rifle shoots best groups with factory ammo so far. I have floated the barrel and that did make a huge difference in accuracy consistency but not with hand loads. I've got Remington brass, Remington 9-1/2 primers for magnum and the three powders listed. For what it's worth, I have found that the old mans .30-06 shoots 168 grains into .125 groups with 55 grains of IMR 4350, CCI BR-2 primer with a Remington ADL. Any help for the 7mm in a ruger mark2 m77 is much appreciated.