I had a 300 win mag about 10 years ago and shot a whitetail at about 70 yards right behind the shoulder and the exit wound was about the size of a softball.
Also, did quite a bit of damage to meat with a 180 grain bullet.

Would the 300 WSM do the same thing? If not, what would be the best bullet to use in the 300 WSM? The last two years I have been hunting with the 270WSM and have killed 2 deer: 1 mule,1 whitetail and one cow elk. They all dropped where they stood...and I mean RIGHT NOW! One deer was shot in the chest as it was angling towards me, the other was shot in the chest as well as that was all I could see of it cuz it thought it was hidden from me in a hollow. The elk surprised me when I came around a corner and I had about 2 seconds to get off a shot. I hit it in the neck and it went down like lightning. The deer were shot with 130grain silver tips and the elk with a 140grain failsafe