it isn't the rifle, in most instances, that should be questioned when hunting an animal like elk. it is the cartridge. in other words, if a rifle has a 'decent' length of barrel to get 'decent' velocity/accuracy out of the proper cartridge/bullet combination, then the rifle is proper. if the rifle can't get the needed velocity or accuracy out of a proper cartridge/bullet then it is, obviously, not the rifle to choose.
in other words, i'd not go after elk with an 18" barrel'd rifle if there is ANY chance that my cartridge and bullet can't get the job done on a long shot. why handicap yourself if the elk is 350 yards away on what is often the trip of a lifetime for many hunters? if you live in the elks' backyard it may not matter, however, because there's always a chance at 'some' elk tomorrow.
on the chance of making a long shot on a rare hunt after a magnificent elk, i'd use a Handi with the proper bullet/cartridge. a .270 or larger cartridge with a .22" barrel would be my recommendation; with a .30-06 in High Energy or Light Magnum variants being a good idea i'd think.
ss'