Re: Ambush Method for Moving Targets
Kraig's response would apply to tracking, not ambush. There is no 'lateral movement of the bullet' (well, none that matters anyway), but stoping when tracking will leave you shooting behind, because the lead you are holding decreases if you stop the movement prior to the shot breaking.
In ambush, you are not moving the rifle at all, you hold on a point in space, wait for the correct lead to exist and fire, following through exactly the same as on a shot for a stationary target. As Graham says, you must know your trigger, this is a time when the shot must break on demand, but without moving the rifle by jerking it.