Pse-archer
Bigbulls gave you the scoop. He is right. Not enough info from you. If you want to shoot Elk at normal distance’s (muzzle to 300 yards then a 30-06 would do just fine) any thing over this and one should try the lost art of stalking. Be that as it may, may hunters want to shoot farther, and that is when the 300 magnums come in. The 300 Winchester is the most available over the counter round of the list you picked. It has a well deserved reputation as a fine Elk rifle. Reloading components are plentiful as well as rifles. I had a Remington 700 BDL many years ago but sold it for a new 30-06. I now use the 308 Win.

Hope this helps
Hornet Man