Frank,
FWIW, neither session was shot with a game gun. The large grouping was shot with my 12ga O/U comp gun with (virtually) fixed chokes of .018/.018 at 15 yds; the 3 bird targets were shot with my 16ga SxS comp gun with fixed .016/.016. The purpose was to visualize the relative merits of different spreader technologies, as opposed to finding a task-specific load. I might add that in a separate session I tried the multi-colored centerpost wad (similar to the soda straw technique)and found virtually no spread relative to a control, with perhaps a negligible disruptance of the core.
I don't employ spreaders for hunting, preferring 2 barrels, 2 different chokes and possibly 2 different loads to achieve as near perfect patterns as I can at 2 common distances for the game involved. In other words, my grouse 20 is choked .005/.015 and the patterns at 20 and 30 yds respectively, with the same 1 ounce of #7.5, are virtually identical. I haven't destroyed a woodcock or grouse since I made that choice, and I doubt anyone would suggest I'm undergunned. Likewise, my pheasant 12 is choked .015/.025 for first and second shots at 25 & 45 yds, but with #6 and #4.
My hunting shots are much more predictable than a clays course and my method for being prepared for any target is to choke both barrels for the longest shot I'm likely to encounter.
For the last decade my sporting clays philosophy has been 2 chokes.....no-choke for ridiculously close and one choke for everything beyond 15 yds. Basically cylinder and modified. But now I'm shooting fixed-choke Foxes almost exclusively, I've been interested in a spreader load that would duplicate a cylinder tube (or even threads). I think the disperser-X technology is really slick in that it produces the most even patterns (notice the absence of hot cores) I've ever recorded but really doesn't buy much additional pattern size inside 20 yds where I need it. The polywad disc gives the most dramatic pattern spread, but at the expense of severe patchiness, even the occasional donut pattern. I think they are much too risky for any straightaway target but offer perhaps the best option on a silly-ass crosser at 40 feet. Actually, that's not so bad. They really do help me on very short, fast rabbits but I distrust them so much I'm not likley to get dependent on them for other targets inside 20 yds. Also, the polywad is not dependent on high pressure and/or velocity; I get similar results with very mild loads.
best, Mike
