I concur that mag primers would be best, especially if you are ever using your loads in colder weather. I usually go to a mag. primer at 60 grains or so powder and greater or if it is a ball type powder...
I have used both the Fed 215 as well as the Winchester WLRM primers in my 270 WSM and haven't found any measurable difference in velocity or accuracy -- and I use a chorongraph. Right now I can find the Win WLRM primers in the stores but not the Fed 215's.