You guys have helped me tremendously in planning my hunt of a life time and I am seeking more info. Well so far I am going to BC to hunt Goats and Mule Deer and have worked out my outfitter and have bought a new 300 Ultra mag to take along. Here is where I'm stumped I am getting ready to put a Leupold 4.5 x 14 on it and I can't decide on a 40mm lense or a 50mm since I have never been north of the border I am not sure which would be best? any advice.