.223 is ok for deer if you pick your shot and can shoot. If not Id go with more gun at least the .243. As for 30-06 7-08 .270 as over kill awhole lot of hurters use these and the 30-06 is probly the most used caliber in the US. As for .223 going away ROFL the US military is still using it strong so dont think for a min that it will go away anytime soon.

3DNWV