I have a 12 twist 25-06 McGowen and it sends anything I load in to it with out a fuss, don't forget that a 25-06 holds 15 grains more powder than the 243, so that in itself will take care of any issues you might have, my favorite load is 63gr of RL17 topped off with a 70gr sierra Blitz King, 4200+ FPS every time rain or shine.

Dean