Data did not call for mag primers just 9.5 not 9.5 mag
I know what you mean by changing primers .
I have a 338 decide one day to make 4 sets of 4 shots on same target
All the same load ,just changed primers cci, fed 215, Win,rem 9.5 mag.
All the years i shot this gun i could only get a 3 inch group at 100 yards
The rem 9.5 M pulled them in . All 4 shots touching.
not just luck that day ,but everytime I went taget shooting