I'm surprised at the number of guys picking the old tried & proven 300 Win. mag considering all the new hot rod cartridges out there. The old Win. mag would be my 2nd choice but with a 150 grain bullet screaming.
I prefer lighter bullets & maximum velocity, one of the reasons for choosing the STW. I'll probably be scoffed at, but in my STW I shoot 140 or 150 grain bullets at hyper velocity, most primers flattened. Barrel life? Lots of companies make new barrels & it's only money.
In the beginning I mentioned deer size to big game animals. Well the largest animal I hunt is an Axis exotic, max around 350 lbs. but mostly antelope, whitetail, & mule deer in wide open country where 400 yard shots are normal.
Jim D