The only issue I ever had with elk was on a medium sized cow in which a 117-grain Hornady .25-06 factory load only penetrated one lung and it ran a little ways. Out side of that I've killed both cows and bulls with .270, .30-06 and a couple of .300s on both guided and DIY hunts. Most of mine have been with .270 and 130 Hornadys. I would use whatever you want if you plan DIY. Use whatever the guide wants on guided. I find it annoying but sometimes guides have strong opinions on a cartridge or bullet, and it makes it easier to go with what they want in my opinion.

Last edited by DesertMuleDeer; 10/02/21.