Last year, while hunting with my son on a RFW property here in Colorado, a hunter did just that- shot at a cow elk, thought he had missed, shot at another cow, and ended up with two dead ones and a mess to sort out with the local DOW officer.
My own experience with elk reactions, after shooting a couple dozen or so with various weapons, calibers, etc. is that the usual reaction after the shot is little or no reaction at all- animal just stands there and falls down after a few seconds, or walks slowly away before collapsing.
The few instantaneous DRT's have occurred while using good ol' cup and core bullets out of a 7mm Rem. Mag., of Sierra and Speer persuasion. The most delayed reactions have occurred with 50 cal. muzzleloader, and with 200 gr. Swift A-Frames out of my .300 Wby. I no longer use those bullets for elk, choosing instead to go with 165 gr. Barnes TTSXes, with much quicker results. The Swifts were bought to use in Africa, and used on several elk as a 'warm-up' for Africa- IMO, way too tough a bullet to use on elk-sized game here in the US.
