My experience. A big Shiras is usually heavier than a big Rocky Mt. elk. A big Rocky Mt. elk is often heavier than some Shiras. If you are talking Roosevelt elk, they are closer in weight when both are big, imo. Antler width does not tell you much about the weight of the Bull. We’ve killed two WY Shiras, been around a couple others. Both of our kills were very big bodied old bulls, 32” and 42” wide. 32” bull was the heaviest. Seen other Shiras that had better antlers, yet were noticeably smaller in body. Both processors we took the moose to commented on their weight, so I am guessing the two we took were heavier than average? Shiras have very long legs, are very heavy in the head/neck/shoulders, just built differently than elk. Moose seemed to have thicker skin too. Been around a bunch of elk kills, including big OR rocky mt. bulls. My experience anyway, which may be jaded due to the large sized Shiras we took. Regardless, a big bull of either species is a major chore, especially if you want to keep the hide or at least most of it.