A couple of years ago Wallace Labisky did a quite extensive pattern testing on various types of shot, all under otherwise identical conditions. I forget for sure where this was run, but seem to think was in the Rifleman. His "Best" patterns came with a high antimony, "Unplated" shot of high quality, forget the brand name now. Hard lead, nickle plated shot was very close behind, no real significant difference, but again the results with plated depended "More" on the base lead than upon the plating itself.
I knew a quite successful TN "Bird" (quail) hunter who, early in the season shot #8s & late season after birds were all older & heavier feathered he switched to #6s. I suggested to him to try #7½s on the late birds. His reply, "NO" #7½s are chilled shot #8&6s are drop shot. Those 7½s are too hard & will punch right through a bird without flatting out & bird will fly on.
