.300 Win Mag is a good deer gun.

I would be one of the guys who would say it is overkill for deer. It cant do much more than a 30-06 unless you are planning on shooting at 500 to 1,000 yard shots. And because of the recoil most people will shoot a 30-06 more accurately. I would also agree that if you plan on hunting elk or bear it is a good choice. But if you are only going to hunt deer use the 30-06. If you must hunt deer with a .300 Win Mag I would also agree that 150 or 165 gr. bullets are a better choice than 200 gr.