You need to find the right bullet and the right speed your bullet likes in your barrel... This is a labor of love, I start with Nosler Accubond... 180 Gn... Then build 5 with Powder #1, Lets say RL 17, 1, at 66.5, 2, at 67.5, 3 at 68, 4 69, 5 70. So your building 5 rounds at each level of powder. Yes, 25 rounds for 1 powder. Then powder #2, Then #3 and so on till you find the one that matches your barrel exactly. I do 5, You can do as low as 3 or 4 each, But I like to see the groups 5 rounds make. My 7 RUM likes the highest max powder charge Nosler recommends. And I shoot 1000 yards regularly, But only at targets. My hunting limit is 700. If you can't find one that groups, then move on to another size manuf. and try that. Yeap. It takes some time, and can be frustrating, but once you've got it. You've got it. Many gun Manuf. charge big $$$ for this service and they make you buy their ammo only.