When I was a kid, in the midst of the Vietnam war, someone told me that bullets fired from M-16s tumbled end over end, rather than spinning nose forward like a spiraling football. Even as a kid, I wondered how that tumbling would affect the M-16's accuracy.
This isn't a rumor, but a true story: As a crime reporter for a newspaper, I once went out to the scene of a shooting. The victim had been shot point-blank in the chest and abdomen with five rounds from a .25 auto.
When I got there, the victim walked out of his house and got into the ambulance. He was in obvious pain, but the five .25-cal wounds obviously didn't incapacitate him. I realized than that the .25 was pretty much worthless unless you're fending off angry rabbits or hamsters.