Re: What speed of single file elk walking?
I am assuming that they walk about the same speed as a horse and the speed of a horses' walk varies quite a bit. but an average of 3.5 miles per hour is pretty close on level ground with no "lolly gagging". This means the elk will have moved 4 feet in the .8 sec. flight time you mentioned. But leading by 4 feet could be too much if they are quartering and not traveling perpendicular to line of sight. Even leading by two feet could be a miss if the elk stops walking just momentarily the instant you pull the trigger.
Moving shots are tough because there are so many variables. For instance, if they're moving 5 mph, they've moved nearly 6 feet in .8 seconds. Pretty hard to guage 3.5 mph vs 5 mph without some kind of windage marks in your scope and a way to time how long it takes for them to pass X distance in Y seconds.
Just my opinion, but .8 second flight time is really reaching on a moving shot. Not saying you can't do it, but I think I'd be chicken. Too easy to make a gut shot instead of a shoulder shot. Again, just one mans opinion.