I've just recently taken delivery of a Sako 85 Hunter in .243, I took the rifle out for zeroing and was achieving reasonable groups at around 100yds. However on a second outing despite running the barrel through with a clean patch before firing, the odd round appeared to shoot wild. I would then obtain a couple of shots in a nice group, before again a wild shot, usually high. I am using factory ammunition (Federal 100 grain)
Is it true that I may need 50 - 60 rounds through the rifle to bed in the barrel?