Wildweasel,
I do not have a chrono., but my guess is that your velocity will be somewhere in the neighborhood of 1300-1400 fps. Probably closer to 1300. It sounds pretty meager, but 495 gr. of lead at that speed will penetrate like a bunker buster.
I ordered my 460 grainers about 4 years ago from the guy in Utah because I was wanting to work up a true power load in a full size .50 conical to someday fullfill my dream a taking an elk with my sidelock. I quickly discovered that this load was the most accurate thing I have found. I know that 460 gr. may not be necessary for the local whitetails, but it is nice to put a shot exactly where you aim it.

C. Davis