Man, I had a nice long reply to this all done last night, but computer gremlins or something didn't send it with the quote in my reply above.
This is just my opinion, but I'm not so sure that ballistic gelatin is the greatest test of how a bullet performs. I know its the standard for the manufacturers to show off how great their defensive rounds are, demonstrating penetration, etc, but thats not how a bullet actually performs when entering a human or an animals body. There are obstructions in the way like buttons, zippers, etc that can have an effect on the bullet before it actually penetrates tissue, then there is the skeletal structure that is just under the skin way before any vital area.
Again, just my opinion, but instead of shooting through some layers of denim, or sheetrock, they should actually put some zippers, cell phone, necklaces, in front of a rack of ribs, then into the ballistic gel to get true terminal performance.
I will say that the bullets/loads manufactured for self defense in the last 10 years have marked improvement from what was available in the past.