I am fixing to start a new rifle and going to order the barrel next week, the question i have is, i am going with a Krieger barrel in a 1-13 twist and i was wondering how many groves would be best 4 or 6 ? The caliber is going to be a 6-250 . I was just wondering if there were any major differences between the two as far as accuracy and fouling were concerened . Thanks for any help .