You can take what jmr40 said to the bank.
I have and use IMR4064, IMR 4350, IMR 4831 and Varget for 75%+ of my bottle neck rifle loadings.
In my experience, .308 Win. gets Varget first and IMR 4064 second with bullet weights up to 168 gr. IMR 4350 with bullet weights of 170 gr up to 180 gr. Anything heavier goes in the .30-06.
.30-06 gets IMR 4350 for bullets from 150 gr to 190 gr. 200 gr and above get IMR 4831.
Varget is awesome in the 6.5 x55 Swede up to 140 gr bullets with IMR 4831 being outstanding with 140 gr and heavier bullets.
Varget also works very well in .243 Win, & 6mm Creedmoor.
Overall, Varget is a very good choice for most rifle cartridges. The old standbys of IMR 4064, IMR 4350 and IMR 4831 are really tough to beat, though. Find what your rifle likes and buy an 8lb. jug.
But there will always be us old guys that just plain like to putter around in the loading shop so we will buy a powder, try it and end up going back to our old favorites.