Re: shooting a running deer
If you cannot practice the scenario, dont do it when you hunt. If you have a range with fast movers, and you can put them on a killzone sized target every time, your good to go. Most cant do that. Most that say that they can, cant.
If you have more than a 4 power scope on the bottom end, toss the idea out.
I use scopes that have a low bottom end magnifacation. I practice "swinging" on a stationary target with a rimfire in the off season, as well as instict shooting. I very rarely do it, and when I do its very close, a follow up shot, anchoring shot (ie, moose running into a swamp), or running straight at me. The biggest thing is to be 100% sure that the shot is going to be a kill shot and its safe.
So I guess what I'm saying is that it's best to not take the shot, but to practice for when its needed.
Since this is a Long range forum, I will say that there is no reason to shoot at game on the run at long range. There are enough variables with long range hunting, adding lead time and target velocity/direction is just to much to handle.