RE: Best caliber
If your in thick cover and under 150yds, get yourself a 12ga. I've seen nothing that can drop a deer quicker, including the .30 cals. With the shotguns they have now they're good out to 200yds (with plenty of bench time). If your stuck on a rifle get a .270 wsm it has the same same ballistics of the 7mm Remag, with a little more punch. My two cents.