RE: deer rifle
This sounds like my brother who has the best of every piece of hunting gear but hardly ever uses any of it.
Anyway, a 300 mag is probably overkill on deer. For a better all around deer cartridge that is capable of reaching out to 400 yards (I wouldn't shoot that far due to large chance of injury), a better cartridge would probably be the 270 WSM. 270 WSM is plenty for any deer. You also get to say you are shooting a "magnum."
P.S. Got a 270WSM last year, but before that a plain old 270 or 30-06 never let me down.