The gunsite information is quoted directly from the FBI tests of "layerd" 5/8 inch sheet rock. They built a shoot box with layers of sheet rock with equal gaps between them. The shot various rounds at various distances and measured penetration.
So the 9mm would go through (let say) six panels, and the .5.56 would go through maybe 5 or would tumble so badly they would shoot out of the side of the box...and that was a "success".
Unfortunately if you built a "normal" home wall and shot through it...the results would be entirely the opposite.
The 9mm embeds in the outer wall in many cases...the 5.56 would sail right theough and end up about 200 yards down range. Many companies and departments followed the test criteria and it supported exactly what the FBI said. When we did our tests were near identical, but when we built a simulated house with walls glass and sheetrock set on studs and designed to be two or three walls in a house with external hardboard siding...the 5.56 was a mocu more dangerous round. Not to mention the problems and distance lethality with shooting through glass.
So the 9mm would go through (let say) six panels, and the .5.56 would go through maybe 5 or would tumble so badly they would shoot out of the side of the box...and that was a "success".
Unfortunately if you built a "normal" home wall and shot through it...the results would be entirely the opposite.
The 9mm embeds in the outer wall in many cases...the 5.56 would sail right theough and end up about 200 yards down range. Many companies and departments followed the test criteria and it supported exactly what the FBI said. When we did our tests were near identical, but when we built a simulated house with walls glass and sheetrock set on studs and designed to be two or three walls in a house with external hardboard siding...the 5.56 was a mocu more dangerous round. Not to mention the problems and distance lethality with shooting through glass.