Not exactly my finest work but I did manage to give three variations of defensive shotgun shells a comparison across three different guns. Sadly I could not remember where I put my big bulls eye targets. So I had to use thin 11/17 paper - which kinda sucked. Target paper is generally heavier and thicker.
For scale, the circle in the center is three inches. The distance may seem unconventional but I decided 20 feet is about the distance one is going to encounter in a home defensive situation. Very possibly less, but not likely to be more. Excluding those who live in mansions.
The patterns were remarkably the same at that range. Which means don't spend a bunch of money on defensive ammo for home defense. Federal or Remington plain vanilla 00 or 000 buck gets the job done. The 000 buck is slightly bigger than 00.
The guns were the Beretta 1301, Mossberg 940 and Shockwave. At twenty feet, the length of the barrel was not much of a factor. The groups were slightly wider with the Shockwave but not much.



Interesting that at such a close distance only once did the wad hit the paper. They either went over or under. I'm not sure which.
With the Shockwave, I always load alternating 00 buck and slugs. In this case, a Winchester deer slug. I tried to shift my point of aim slightly for each gun so there wouldn't be just one big hole in the center of the thin paper. I was too lazy to do one target for each type of ammo and it was looking like rain so I did this hurriedly. All three groups were between 3-1/2 to just under 5 inches. The Shockwave being the largest. No surprises there. I usually run an IC choke for defensive shooting (although I dont think it matters all that much) and that's what's in the Beretta and Mossberg. No choke in the Shockwave of course.
So this sort of half-assed science project revealed two things: 1. Good ammo is pretty much all the same at close range; 2. No matter which smoothbore you decide to use for home defense, the bad guy is fucked. He's going to have 8-9 nasty holes in his chest. Or if you aren't a good aim, his leg or arm may or may not remain attached.
I planned to also pattern the 20 gauge Shockwave but ran out of time. I may be able to do that later in the week.