It wasn't until this thread that I gave too much thought to the issue. I always figured that 4 Buck pellets would hit like 22 Short rounds. So to give myself a little perspective, I decided to compare the two side by side.
One round of this,
(According to the OP)
Versus 27 rounds of this,
View attachment 1025925
Well, the 4 Buck pellets are .24 caliber ~ 20.71 grains each at a listed 1325 fps (80.74 ft-lbs and 27.44 PF) each. (1.25 ounce load)
The .22 Shorts are 29 grains each at a listed 710 fps (32.46 ft-lbs and 20.59 PF each)
Multiply both by 27 and we get 2180 ft-lbs for the 12 guage load and 876 for the cluster of .22 Shorts.
Well, the 12 certainly has more potential to do a lot of damage but the .22 Shorts can potentially be placed with more precision. If I had to chose between the two for HD (at close range), I wouldn't hesitate to pick the 12 guage loaded with 4 Buck (as shown in the picture above).
Is any round guaranteed? I don't think so, but unless you're only choice is a single shot, it's my guess you can always just rack again/pull the trigger again and repeat.