I have seen a 7x57 that I like the look of to replace .243. Good all round calibre. The only downside to which is that it is not legal in France.
Given that there is sufficient length of action to take the longer round can you lengthen the chamber from 7x57 to 7x64 so as to make it legal in France if I ever needed to take it to France.
7x64 does have a bit more thump than 7x57, but it seems to me that with 7x57 and good handloads you don't give very much away in terms of muzzle velocity to the 7x64.
Principle reason for wanting to change is that am less than impressed with 243 on Red deer at 150 yard range - 243 is OK if spot on, but one was shot the other day - bullet slightly far forward so hit the shoulder. Bullet smashed the shoulder blade, bullet didn't even penetrate the rib cage.