I spend a lot of range time shooting a Marlin Mod.25 in .22lr, or my Savage .17 hmr to help prefect trigger pull and accuracy. Because they are cheep to shoot and a lot of fun. I sometimes find that with my .308 I will anticipate the firing of the weapon and that causes me to miss a lot more, so I go back to the .22 or .17 hmr until I get it down again.
If you find that you are not getting tight groups with your big dog, then use something like a .22lr to help with the areas that are effecting your shooting. I see a lot of people anticipating recoil when they shoot, and this causes them to miss a lot. I will tell them to go back to a smaller caliber to help fight the bad habits we get into when shooting