Never shot a block of ballistic gel. Never saw one either.
My lay testimony on shot of various sizes as relates to hogs.
#8 field load, 12 bore, 10 yards: One shot stop
#3 Buck, 20 bore, inside 30 yards: Dan 70+/- Hogs 0
#1 Buck, 16 bore, 30 yards: dead pig
00 Buck, 12 bore, 20 yards: dead pig
All in all I found it as reliable as a .30-30, .257 Roberts or a .22 CB Short.
Never saw a shotgun pattern large buck as well as small. Never met a pig that would stop any size buckshot on a broadside shot unless it hit heavy bone. People are a lot like pigs more often than not.
Ballistic vests? Never met anyone who went anywhere without their crotch, including Elvis. Living with a perforated crotch is a serious challenge.
Back to your regular programming....