I've read several people mention wanting to carry larger calibers for personal defense in the winter in colder climates to counter act the effects of additional clothing an attacker would likely be wearing. I just got to wondering...does the extra clothing really matter? I mean even a heavy winter parka is mostly just air. With the possible exception of leather it seems to me that most clothing materials would have a negligable effect on ballistics if any. Further more wouldn't you more worry about an attacker being fatter or more muscular than average? Seems physical bulk would have a greater overall impact on slowing a bullet. Has any real testing been done on this topic, or is this just heresay?