Battue,
Don't know if I ever wrote exactly what you state, "a large Bird like a Pheasant will easily fill a shotgun pattern of large shot," but did point out in my Handloader article on the 28-gauge that one reason it works so well on larger birds is they do indeed get hit by more shot than the smaller birds many people think the 28 works best on.
That article was based partly on deciding to use the 28 as long as possible during a Montana autumn--where the upland birds hunted tend to get progressively bigger and tougher later in the season, due to dove season closing, pheasant season opening and birds maturing. That was also back when sage grouse season lasted as long as the other upland seasons. When the 28 started "failing," I'd put it away and use larger gauges.
But I never did. Found it worked great on pheasants out to at least 40 yards, eventually deciding a handload of 7/8 ounce of hard 7's did as well as any other 28 load. Used an ounce load of copper-plated 6s on sage grouse, and the longest kill was 47 yards on a mature rooster. (The 7's also worked fine on all three of our "forest" grouse--ruffs, blues and the Franklin's variety of spruce grouse--as well as on Huns. But the pattern was a little thin for doves, except at the closer ranges typical earlier in the season. Generally I used 8's or even 9's then.
It was a lot of fun--and eye-opening!
