I would back-off and start all over using 70 grains. Don't be surprised to see your groups narrow all the way out to 100 yardswhile never exceeding 80 grains 777.

In the powder direction that you've been administering,you are looking for a cure-all that's common with slow twists using heavy conicals .... ie... 1-60" to 1-70" twist. Being yours is a fast 1-28" twist with shallower grooves than the slow twists, using less fast take-off powders like 777 usuallydelivers"gooder" [X(]results.

With 45-50 calrifles, the faster the twist - using 400+ gr. conicals, the less powder you need for grouping. As the caliber size grows & twist slows, more powder isneeded for stabilization.

Yeah... there are exceptions to this. Somebody will come on here & say they accomplished 1" groups using your method, but those folks/those fast twist guns/those 100+777 powder chargesare rare exceptions.

What's even nicer about the powder charges I am suggesting isyour rifle flinching-controlissues are eliminated - the need for Sims padsare eliminated & the wife goes near you again because you no longer smell like Ben-Gay...lol