I'm really interested in the leupold vx5 3-15, however I'm not sure which lens (if it even matters) size to get I have 2 options the 44mm or the 56mm. I'll be hunting mule deer with 6.5 creedmoor
Smaller objective allows you to mount it lower and get good cheek weld on the stock.
Personally, I have both…both are fine, but I prefer the smaller objective on mountain rifles that I have to carry a long way and shoot from field positions.