You guys lack imagination. How many feet of dirt behind the dead animal is "enough penetration?" Why would we limit the Whelen to 250 grain bullets?
Is the argument really that there is zero effect by jumping up from 30 caliber to 35 caliber? If that is the argument, I'd argue that you are likely correct, given that 6.5mm non-expanding bullets have been used to kill all of the largest dangerous game animals on the planet many, many times.
The question then becomes, "Why are you shooting a 300 Win Mag, when Creedmoor ballistics kill the largest game, and very effectively?
