You should consult the owner's manual about that. My 10/22 did not specify any sort of break in period, that I recall. I just bought several boxes of a few different types of ammunition, and went to town. Some "match grade" barrels may have different instructions.Got a couple more somewhat related questions: If I do get my rifle and have it cleaned and ready to go to the range on Friday, do I risk any kind of damage to the new bore by shooting "plinking" grade Remington or Winchester ammo instead of Wolf match grade? And is there a barrel "break-in" process I should follow? I might be making more of this than I need to... just would hate to damage the bore.
Consensus seems to be that you need to shoot a few mags worth of any given brand of ammunition before you start to see consistently precise results. The hypothesis being that you need a consistent coating of the lubricant from the rounds on the surface of the bore, which takes a few rounds to get deposited.