Raith, i agree. Most people should be trained, with any firearm, they own or intened to use. And Traing should be a ongoing thing. But the truth is, it is only a small amount of people who will take the next step(training). So thats why, i say to use bird shot #9. They will be less likely to kill there family when they panic and start shooting.
Some dumb ass with a 12 guage shot gun loaded with 00buck, and slugs. has a real good chance of kill the neighbors, and there family. As panic and adrenaline sets in. The bloob pounding in there ears, and they cant hear, Dont shoot Daddy!!
Personally, I use a Mossberg 500a, Pump, with the first round being #4, then the rest 00 Buck.