I am assuming you will be hunting elk? I have been on many successful elk hunts (and few where things went sour.) Our camp has taken over 100 elk in the past 25 years. Some observations I've made over the years: We limit our shots to under 250 yards and take only broadside shots. Either of the bullets you chose will work fine. BUT the A-frame will penetrate better with a shoulder shot or if the shot isn't perfect. Having two holes in an elk is almost always better than one, as there is a better blood trail. A big bull elk is a tough animal. I think equal to any Africa antelope of similar size. When we wounded animals, it wasn't from bad bullet construction but from bad bullet placement. We are big fans of Barnes TSX/ TTSX. Have seen elk taken with 7-08, 270 win, 30-06, 308 win, 358 win, 7x64 mauser, 7mm Rem Mag., 375 ruger, 375 H&h, 450-400 nitro express. All of them work with good shot placement. If you think you can get closer, do it! Easier to kill a bull at 200 yards than it is at 400.
Sorry for the long post... Probably more information than you were looking for! (Also advice you receive on the inter web isn't worth very much ; )