Back in the day, late '80's and early '90's, I shot on the department pistol team. Once a year or so, we'd travel to Mountain Brook PD range, just outside of Birmingham, for the purpose of choosing match ammo for the upcoming PPC season. We used this range because it had a Ransom Rest setup at the 55 yard mark, off to the side of the regular target bank. Our primary goal was to find ammo lots that performed well in our custom, heavy barrel PPC guns as well as our 6" Distinguished guns (either Smith 586's or Colt Pythons). We also shot 4" Service matches, but figured any ammo we chose from the testing would serve well in the Service match because we never ventured beyond the 25 yard line.
More than once, just for fun, our 4" Model 15's, 10's, 19's, and 66's found their way to the ransom rest. For the most part, we found no statistically significant difference between the 4" guns and the 6" production guns. Every now and then we'd find a gun/ammo combination that really worked well, but for the most part, with a given ammo, you could shoot groups with the 6" 586 and follow it with groups from a 4" 15 and have a hard time figuring which was which unless we marked the targets.
Our testing was not scientific, but it was a boatload of fun. Too bad we never saved any of the results for future review. We all shot 6" guns in the Distinguished matches, but that was mostly for the extra sight radius, not additional inherent mechanical accuracy.
I kinda' miss shooting PPC matches, but I Really miss the Saturdays at the range with my friends and their families...........