I would try both. I have used magnum primers when others said I didn't need to, which resulted in tighter groups. This was in non-magnum cartridges, .22-250, .243 and .25-06.
I think I read somewhere that Roy Weatherby had Federal make the No. 215 LMR for his cartridges which were burning over 50 gns of powder.
I use both in my 7mmRM, 26" barrel. JohnnyK.
"The only thing necessay for the triumph of evil is for good men to do nothing."