Too, there is often significant difs with ammunition from the same bbl., e.g. a high quality trap or target load vs. an inexpensive 'promotional' round vs. a thumping blaster round ... for those who need to feel the recoil to have confidence vs. a reload with seemingly low velocity [<1150 fps] that throws tighter than expected patterns. In any case, only time at the pattern board and shooting multiple patterns & some form of analysis will tell you what's going on with any certainty.
For example, some so-called 'spreader' loads don't 'spread' very much.
Another example that comes to mind was finding that some of those 'rifled' choke tubes that are advertised to open patterns give typical IC results w/most loads. Another was finding that some Remington Premier 27 trap loads in #7.5 produced some well balanced 65% patterns out of a cylinder bbl. in one particular gun.
One can go back and read some of the 'card tests' that were performed in England before choke boring became the fashion to see that differences were being reported even at that time to both penetration and pattern densities with some makers using those results to hawk their 'improved' cylinder borings. Naturally, the powder and shot and ammunition makers too were all claiming superior products. Some of them probably were.
I suspect then as now, irrespective of gun or ammuntion used that the better shots experienced the best overall results.
