I was looking at some data for Gelatin tests comparing different types of 40 S&W loads. What mystified me was that some of the same rounds penetrated much deeper into clothed gelatin than bare gelatin even when the expansion in clothed was the same or more. I can understand when a round expands less and penetrates deeper, but what the heck, more expansion and penetrates deeper after going through clothing?!
Example
The difference in expansion doesn’t seem like much (0.01" if I’m reading that right) however could the increased penetration be due to the hollow point getting a little wad of cloth jammed into it, something that won’t happen in the bare gel?
I’m wondering about that. In most cases I’ve read where clothing effects hollow points, the clothing acts as a plug and keeps the hollow point from expanding.
My WAG, based on Mythbusters slo-mo shots of ballistics gel being shot, is that bare ballistics gel is capable of an incredible amount of jiggling and distortion when it is hit, which would dissipate a lot of energy. If the gel is covered with cloth, that cloth–even stretchy cotton knit–is going to prevent a great deal of the distortion, thus preventing a lot of energy absorption upon impact.