I have a 30 cal. Krieger 26", #5.5 contour in 1:10 twist coming soon. I want to shoot a heavy bullet, like a 210 Berger VLD, or similar. Looking for feedback on weather to build a 300 RUM or 300 Jarrett. I have read that the Jarrett is more efficient and gets the same velocity with less powder. Anyone shooting either one of these calibers with heavy bullets, your feedback would be appreciated.