I went that way 15 years ago thinking I too needed a bigger one! After doing nothing more than blood shooting the heck out of excellent elk meat, I use 270, 280, 308, 30-06, 338-06, and the 35 Whelen with much better results. Never saw difference in performance between any of them and the 338WM given that I did my job and put the bullet where it should go. Other than a lot less bloodshot, that is! Got tired of losing the front end of good elk.
Use good bullets and spend more time shooting! Using a bigger gun doesn't make up for that.