ADB, blanks kill people, but I don't think anyone in their right mind would recommend using blanks for personal protection.
The same thing is true when you look at the gel tests for bird shot.
This is not to say that you would WANT to get shot with bird shot.
This is not to say that you would not eventually die from being shot with bird shot.
From the Box of truth website.
We have done tests with various birdshot loads. Birdshot penetrated through two pieces of drywall (representing one wall) and was stopped in the paper on the front of the second wall. The problem with birdshot is that it does not penetrate enough to be effective as a defense round. Birdshot is designed to bring down little birds.
A policeman told of seeing a guy shot at close range with a load of 12 gauge birdshot, and was not even knocked down. He was still walking around when the EMTs got there. It was an ugly, shallow wound, but did not STOP the guy. And that is what we want... to STOP the bad guy from whatever he is doing. To do this, you must have a load that will reach the vitals of the bad guy. Birdshot will not do this.
When To Use Birdshot
A friend of AR15.com sends this:
"I saw a gunshot victim, about 5' 10" and 200 lbs, taken to the operating room with a shotgun wound to the chest. He was shot at a range of six feet at a distance of just over the pectoralis muscle. He was sitting on his front porch and walked to the ambulance. We explored the chest after x-rays were taken. The ER doc had said 'buckshot' wound, but this was obviously not accurate.
It was # 6 shot. There was a crater in the skin over an inch in diameter. When the shot hit the level of the ribs, it spread out about five inches. There was ONE pellet that had passed between the ribs and entered the pericardium, but not damaged the heart at all. As you say, 'use birdshot for little birds.'"