Don,
I'm not sure how much you want to expand the research. But I'm leaving that up to you.

One nagging question I have and probably many others is the comparision of steel vs lead on the choke area stress. Then further comparisons of smaller vs larger shot size in both lead and steel. All testing should probably be done with like loadings from same mfrs when doing the shot size comparisons, of course.

I also have a chronograph if you don't have one.