At our morning senior citizen problem solving session we all have questioned primer interchangeability. I (we) all figgered that push come to shove, anything that fills the hole and stays put will work.
standard caveat applies: my loads-my risk. My normal load for my springfield '03 is 25 grains of R-7 and a .310-185 Hoch bullet gc'ed. So I loaded up 50 and used large rifle, magnum large rifle, and large pistol primers. As far as I can tell, there was no difference. The noise and recoil was the same , the primer flattening looked the same and the groups at 50 yds all looked the same. Later at the bench, resizing also felt the same.