I have an opportunity to hunt 8 days in Colorado for elk and mulies come October and this will be a first for me on both animals. I have been getting my fitness in order and evaluating my rifle. To the end of the latter I am down to 3 choices and am having trouble deciding. I have hunted deer and hogs , yotes etc all my life so I am not new to hunting but when trying to decide on a weapon for animals I have no experience with is really bugging me. My thought is with all the effort, time, money and sacrifice I am putting into the prep and hunt I would certainly hate to be stymied with a bull or mulie hanging out at 500 -600 and not have the energy to put him down quick. This has led me to the 270wsm 300wm and 300wsm. The issue is that when I look up the ballistic chart for remington on all 3 calibers and read the energy and velocity on paper all three are pretty darn close. The 300 and 300wsm shooting a 180 siracoco is reported to have 1762 and 1790 fpe with the 270wsm having 1748 shooting a 150 gr premier accutip. All of these are for 500yards. 1762, 1790 and 1748 all seem pretty close and if that means that they are then the 270wsm would be the ticket with a lighter overall rifle and less recoil. So am I understanding this right? does the mass of the round play more of an role once its inside the animal with a higher Ke to do the job or are they really all this close that it matters not?