I carry a Seecamp .380 when small size is important.
Wish I could always carry a 12ga shotgun, but obviously there is a compromise.
Here is the type of info that makes me feel comfortable carrying my .380:
http://www.goldenloki.com/ammo/gel/380acp/gel380acp.htm
You think 11 inches of penetration with this [Broken External Image]
is really gonna do anything? I mean, come on man!!!