I think you're on the right track, but also think you are pushing your 9.3x62 pretty hard. "able to reach 2515fps without any pressure signs" You likely meant to say you didn't observe signs of unsafe pressure. Just because primers are not flat or cratered, or the bolt isn't difficult to lift doesn't mean its actually a safe load. If it was me, for confidence that I was in fact not stressing the action and cases too much with such stout loads, I'd load up a magazine full of those maximum loads, shoot them, reload the same cases, repeat 5 times. If your four or five cases survive that without expanded primer pockets and no excess stretching you likely do have a safe load. Good luck on your buffalo hunt.
