I shoot everything from 40 to 75 grain pills in 22 caliber rifles. The main reason I use different grain bullets is the distances that I shoot.

From 0-250 yards I shoot a 40 grain bullet
100-350 I shoot a 50 grain bullet
200-600 I shoot a 75 grain bullet

I normally know what field I am going to hunt before I go, so I take the appropriate rifle with me. If I only had one rifle it would be a 22-250 with a 1in8 twist. Fortunately I have several, with several twists. Tom.