Nitrox,

I just read your post and found it interesting and informative.
I also found it compares well with the the information in the book "The Double Rifle Primer" by Cal Pappas. I mean that as a compliment. Keep up the good work.

PS I recognize the .470 shot group provided on AR by Buckstix.

Here is the 50 yard regulation group shot with my Simson Suhl .405 WCF by Aaron Little:

Such regulation is a confidence builder should a second shot be needed- so far not necessary!