If you're looking for a rifle to go after just deer in Florida then a bolt action .243 will do for you. I can't speak for the 7mm mag or 270 WSM. But I've heard that the whole WSM system, although having the same velocity and same impact power as their more common counter parts, aren't selling as well as they were supposed to and will probably not last. So I would say go with the 7mm mag. I would first work with the rifle that you have and see if you can improve your accuracy. I personally prefer bolt action rifles or single shot because I think they force you to count on your first shot due to the fact that you don't have that second shot.