RE: 7 rem mag a good deer rifle?
Why do you say once you sight it in you will only hunt with it? If you plan on taking long shots you'd better be doing a LOT of practicing, and you MUST sight your gun in every year and every hunting trip. You owe it to each and every animal you pull the trigger on.
A 7MM mag is a great cartridge as are others. It is not too much gun, there is no such thing. Dead is dead.