No it wasn't old ammo. So far as the milk jug goes the bullet impact over pressurizes the jug and they are easy to explode. Not really a good indication of its effects on flesh. If your really curious, go buy a large piece of beef, or some scrap hog with skin, put a piece of clothing like denim over it and shoot it. Then cut it away to measure penetration and expansion. I had considered .380s etc before seeing that deer. Having cut the bullets out of it, I came away with the firm impression that anything less than .38 or 9mm just wasnt sufficient.
I mean even the venerable .45ACP with a 230gr Hornady XTP isnt a man stopping round all the time. As an example here is a link to an incident where a CCW shot a man 4 times in the chest (all eventually would have been fatal wounds) and the attacker did not slow down. He eventually had to shoot the guy in the head to stop him.
http://www.theshootist.net/2009/01/one-man-got-involved-perry_12.htmlI intend to carry just as large of a cannon as I can conceal.
So far as concealment. I carry large and small guns. The small ones I usually carry in either a jacket pocket or pant pocket inside a pocket holster to protect the trigger and keep the gun oriented for the draw. Remember that an auto shooting from a jacket pocket etc is a one shot weapon. The fabric will likely jam the gun after the first shot as it restricts the slide movement. For that kind of deep concealment I choose a J Frame Smith & Wesson hammerless revolver. You could empty that thing from within a jacket pocket if the need were to arise.