Larry;
Put your thinking cap back on for a bit. Fact is, at skeet ranges the 28 is capable of running near perfect scores, with misses being the fault of the shooter more so than the gun. "IF" one is breaking 98-99 out of 100 with the 28, then maximum improvement which would be possible would be 2% even if a 10ga with 2oz of shot was used.
Sort of like if I take a .22LR to the squirrell woods & kill a TN limit of 6 with 6 shots, I would not expect to have a higher kill/shot ratio if I carried a .32-20, But, on the other hand, If I were shooting Coyote??
Take the 28 & the 20 to a handicap trap range. Start at the 16yd line & keep baking up after firing a statistically reliable numer at each point. If the 28 seems to still retain the same effectivness, First pat your self on the back, You're a great shot. But be well aware it will have done so because of the afore mentioned central density of the pattern either from a higher percentage overall pattern or from an increased percentage of the central core thickening, Either which is accomplished at the expense of a reduced effective kill circle, there simply is "No Free Lunch".
Thanks, Miller . . . having run a few straights myself at skeet with the 28ga, I'm quite well aware that it can be done. (And having seen better gun hands than me shoot skeet with a .410, I'm convinced I could not do it with one of those.) But you're not looking at Brister's reference. He was not talking about the best skeet shooters in the world. Rather, he was talking about B class, which is pretty good, but certainly not great. These are guys who average 93-94% with a 12ga, so they're not likely to average 98-99% with a 28. (And remember, this is a pretty large data base we're talking about here--not just one guy on one day.) The same guys averaged 91% with a 20ga, and 90% with a 28ga. That means they're dropping 1 target out of 100 when they should have, to use your words, "a reduced effective kill circle"--because they're throwing a lighter shot charge. So apparently that effective kill circle has not been reduced by much--at that range. It likely would be, if those targets were out beyond 30 yards. But at skeet range, the gun gives up essentially nothing to the 20ga--which is why it's such a good choice for game usually shot at close range--like grouse and woodcock, and quail. Not a good choice, for sure, for birds shot at longer range and/or requiring shot sizes larger than about 7 1/2 because, as you said, there's no free lunch.
