If you are going to go to the trouble of working up the brass, why not make a 25 WSSM? It would be small light, pack the punch of the 25-06. I think the 25 WSSM is probably the best WSSM at least from what I have read (I haven't shot one). 25-06 velocity and weights in an action shorter than a short action (.308, etc.). Seems like a great deer round. I'm too cheap to buy one when a box of bullets is so expensive, but if you handload anyway and you have to work up brass for the 257 Weatherby anyway, why not just go 25 WSSM?
No I have looked at 25wssm and decided against it would rather have a 25-06..the 25wsm is the same case length as 270 and 300wsm. It gives up maybe 100 fps to the 257 wthby if that in a 24" barrel not 26".