I routinely carry a snub, a 2" S&W 042.
I've been carrying 125-gr. +P Speer Gold Dots in it for the last several years.
In summer 2010 I had the chance to test some of the rounds by firing them into a trash can filled with water from 10-15 feet away. Not the best analog in the world, but it was what I could do at the time, and Martin Fackler indicates that water testing (via the Fackler box) does give valid penetration information.
9 out of 10 mushroomed perfectly to about .50, "penetrated" about 20 inches of water, and dented the opposite side of the can. The 10th one I didn't recover as it hit above the dropping waterline in the can and sailed into the dirt bank beyond the can.
The Speer ammo is specifically designed to both penetrate deeply and expand reliably at .38 Special velocities, including when fired from a snub.
"The gift which I am sending you is called a dog, and is in fact the most precious and valuable possession of mankind" -Theodorus Gaza
Baby Jesus cries when the fat redneck doesn't have military-grade firepower.