I have been given a Savage short action barreled up in 243 winchester,, have never like this round, so am going to change, what other calibere would the group go with, no real need for it so it is just an in case rifle.

Depend on what "in case" means. For an all around rifle in a short action I don't think you could not go wrong with the .308. Keep the 243 barrel and you would have a switch barrel affair that would cover most of North America.

With just a barrel change, no bolt head changes etc. you can change it to: 22.250, 260, 7-08, 308 and 358 Winchester.
On all of these you should be able to get by with no magazine modifications but the 22.250 might be a little iffy. (mine worked fine)

.250-3000 !!!!!!!!! roger