The 100 gr Partition at about 2800 out of the Bob was my father's "big" gun for elk for well over a decade. He was a hunter, and an amazing field shot. He never had to shoot twice with the Bob and Partitions.
That said, I don't think they are a requirement for close-up deer, given the not-quite-magnum speeds produced by the 257. Shoot what you prefer. They are all good, and they will all work.
Unless he sized it too much I bet his brass lasted a good long time too. That's a mild load for a 257 Roberts.
