I had the exact same issue about 20 years back. Went with the 338 and have never looked back. The 300 is a great choice, but I am very happy I went with the 338 and for elk, it has never let me down. IMHO, the 338 is a slightly better choice for elk, moose, bear. The 300 is slightly better for all around. That being said, I use my 338 on deer, lopes, etc., simply because it is my favorite rifle.