Got the IM's and thanks for the link. I haven't gone through it all, but the info in that link is kinda' freaky to think about. Action-reaction. OODA, it's kinda' like sales- he who asks the questions controls the conversation.
I went back and re-read my posts on the first page of this thread. The story about the dog- birdshot at 20 yards (give or take) made him mad and charge. Point blank, muzzle firmly against his head, birdshot made a single hole that put him down without a twitch. It did NOT cut his head in half, and the shot charge did NOT exit. The gun had a 28" barrel with a full choke too. That is a real story; I was there. Scared me right out of ever trying birdshot for anything but small game ever again. I stand behind everything I said, but...
if ikor says that 00Buck is barely adequate, and 000Buck is better, then I say go with that. Better yet, make it copper plated, buffered, and a 3" shell.
Which brings the question, "which ammo maker do we need to pester to get adequate defense ammo for the 20 gauge?" I would like to see it made by Remington or Winchester, but it might be better to ask the hillbillies at Kent perhaps? Ballistic Products even has 0000 (yes, that 4 zeros) Buck for the handloader, so why not some commercial loads with that? I mean, for cryin' out loud, we can get 00 and 000Buck for a .410, why not the 20gauge?
Just thinkin' out loud...