Again, there are several threads on here showing you are again wrong John.
Faster loads do penetrate farther and kill farther than "standard" loads in the 1400fps range. They do slow down faster, but they are always faster than the 1400fps. There is a specific range where 1400fps #2 shot is not lethal and 1550fps #2 shot still is. That is the point where the faster loads are better, since they are the only loads left that can kill the bird. But at that range you are most likely going to run out of pattern in both loads... but if you spend the time and money to perfect that 1550fps load and make it pattern good at the range 1400fps dies off, it will be a duck killer for those 3-5 yards!
Simply physics shows the faster load is better at a specific point in the flight path, and any idiot can figure that out... its the only shell left out of the two that is even lethal
With the same testing you can get a 1400fps #1 shell to pattern at the same range as the 1550 #2 and have it still be lethal, but then you are not comparing two like shells.
So what I am saying is that speed really does not matter when they are that close together (1550vs 1400), but speed does extend your lethal rage for the individual shot in your pattern. Does not increase the pattern's range, just the shot inside it. Therefore, speed does have a specific place in waterfowling, and to think otherwise is just plain asinine.
You can shoot a 1 3/4 10 gauge load of #2's and a 20 gauge 7/8 1550fps of #2's. There will be a point where the 10 gauge is no longer lethal and the 20 gauge is. Doesn't matter how many pellets are in your shell if you shoot it past where the individual pellets are no longer lethal.