Sustained lead is what you'll hear competition skeet shooters teaching to newbies. And it works well at skeet because you have a whole lot of information you don't have when shooting birds rather than clay targets: where the bird is coming from, when it's going to "flush", as well as its angle of flight, speed, and distance. When you have all that information, sustained lead makes a lot of sense. Under other situations, it makes less sense.
Larry: I think you really hit the nail on the head here. As a competition skeet shooter I find myself 'locking in' in terms of stance with ideal foot positioning weight forward in such a manner where one swings at the waist and ankles rarely if ever using the arms to swing the gun. This is next to impossible to attain in other shooting venues, even trap, but certainly the case in the wilds such as grouse hunting, where proper stance is often times impossible and the shooter must rely on his arms to make 'the move' to target acquisition. Here, and as you mentioned, sustained lead is not very reliable, one reason being with poor stance and using arms to swing the gun, many shooters would be incapable of adequate follow through, I think.
