I am building a custom 300 win and am trying to decide between a 4 and 5 contour barrel from Rock Creek. The other option I was looking at is a 5 fluted to save weight. I want it to be accurate off the bench, but is going to primarily be a hunting rifle. Weight is an issue, but I am a bigger guy. Is it necessary to go to a 5 contour to have an accurate 800-1000 yard gun? A.J. Brown is building the rifle for me. Any thoughts?