I have out-grown my magnumitis too! My next gun will probably be a .243!
I know some say the .243/6MM is too small, while still others will go with something even smaller than the .243/6MM!
To me, the .243 is a great minimum caliber for deer, and the other mid-sized calibers are great too! But, no whitetail, anywhere, REQUIRES a magnum caliber!
I'd say don't use anything bigger than you can accurately shoot, and anything smaller than the .243/6MM, are too small for most hunters! Of course if it's legal, its really up to the individual!