The 300 Weatherby is way small for elk. Bullets likely to make a dent in the hide and bounce off. A 340 Weatherby is in the right direction but a 375 or better yet a 378 Weatherby is getting pretty close. And then if only using heavy bullets - Swift or Nosler Partitions.
I prefer classic. Semper Fi I used to run with the hare. Now I'm envious of the tortoise and I do my own stunts but rarely intentionally