Winchester White box bulk 40 rounds 45gr. This is what other ammo is measured by. It does not work for all but for most it is the best. Use the stickies for more info on break in and such if this is a new rifle.
I have tried other factory fodder including the CT offering from Winchester and found 1.5" @ 100yds from some of them. WW 45gr is under 1" from a bench.