Its a crap shoot at this time, there is some talk of the 25WSSM being in a little larger case than the 243 WSSM. There are 25 WSSM's made from 2433 brass, being shot now and they won't catch a 25-06 in any bullet weight. I have a 257 WSM and am getting velocities very near the 257 Weatherby.
Dan
