i dont know how big the deer are in michigan but in TX a .300 mag is a little too much gun lol, except maybe in west TX for mulies & then only for a little greater range.
if it was me i'd get a good old '06, or a .308 i suppose. personally i prefer the '06 to the .308, a wider selection of bullet weights being the reason, that and the fact that with the wide range of bullet weights available the '06 is plenty enough for anything in the lower 48, its just more versatile than the .308 imho.
also a '06 is a lot easier to shoot well vs a .300 mag, i shoot a LOT of big rifles (.45-70, 7 mag, .300 weatherby mag, .300 win mag, 338 win mag and 375 H&H) and while i usually enjoy shooting an '06 or a .308 i cant say the same for most mags, even a 7MM mag with stout loads, lots more recoil and muzzle blast, and lots harder to shoot well.
also the .300 mag will be heavier than the '06 or .308, or ya will wish it was if ya shoot off a bench much lol.