Elbert, enjoy reading all your test results. I was reading on line last night and came across a shell that I had not seen before and was wondering if you've either seen or tried them.
They are called "Copper Matrix NTF" and apparently it's a slug made of copper particles which are frangible. Sounds interesting but don't know how it would work on different targets. I've not seen them around here but we're limited in places that carry such things.
Know you're not focused as much on slugs but if you really want to see what a shockwave is capable of try some Brenneke Black Magic Magnums. They are not available in 2 3/4 inch any more but the 3 inch ones work well. If you try them use a hard target. I quite frankly haven't seen anything better. We use for bear defense.
Regards