43 grains of H4350 with a 140 grain bullet in a 6.5 creedmoor case is your slow to medium velocity load? What kind of brass life are you getting?I'm not sure why you need more velocity. Maybe if your trying to get from 1300 yds to 1400 yards you need to bump it up. Besides that all veloxity adds is burned out barrels and stretched out cases. I go for the more accurate load at 100 and 600 and leave it no matter what th veloxity is. Usually the slower to medium veloxity do better for me. My load doe 6.5 creedmore 24 inch barrel 43g h4350 2.82 cole 140 grain lapua scenar. Best of luck with development. But remember guns aren't race cars faster isn't necessarily better.