Based on my (limited) personal experience I don't even consider birdshot an option for self defense.
Once when I was in college some friends and I were out hunting in the woods when one of my friends (who was not following the 4 rules of gun safety and who is kind of an idiot) accidentally shot one of my other friends with his shotgun, which was loaded with birdshot. My friend who was shot was about 40ft away and it was in late-fall so he was wearing a heavy coat and multiple layers of clothing. He said the birdshot hurt like a SOB and knocked the wind out of him, however, only about a dozen pellets broke the skin and none penetrated even remotely deep enough to be life threatening (he did have a massive bruise afterwards) and he made a full recovery in just a few weeks.
After seeing how little the birdshot effected my friend when he was shot (my friend was completely coherent and physically active afterwards), birdshot is about the last load I would want to use to try and stop a determined attacker who may be high on drugs and feel even less of an effect.
"It's not the bullet with my name on it that worries me. It's the one that says "To whom it may concern."
Last edited by pokersamurai; 10-07-2012 at 16:10..