My deceased uncle hunted for years with a Winchester model 70 XTR 270 Wthby Mag. His whitetail load was 72 gr. of H4831 and a 130 gr Speer Boattail. I cannot read his load with a 150 gr Nosler Partition, but he used H4831 for that load also. I used the rifle one year with the 150's and it was an honest MOA rifle. I never knew of him owning a chrony but he was an avid reloader. Many of the Weatherby factory loads use Norma MRP. H4831 is only slightly faster in burn rate so I would think it would be the ideal powder to use. Unless you have access to Norma MRP. I can't find any near my home.