While I agree on what our WY statute says (as silly as it is) the idea that a 45 ACP or 45 Colt will not dispatch an Elk at 50 yards or less is just silly. A .452-.454 hole through both lungs of an Elk is just as deadly as a Muzzy broadhead at the same range. I carry my S&W 329 44 magnum with 300 gr hardcasts all the time when fishing the back country where Mr. Griz. lives.
Not sure if I'm "legal" but figure that anything that will penetrate a mature steer, when shot between the eyes, and end up way down the neck, would put a hurt on anything tromping around the Winds, Upper Green or WY range.