This has little to add to the very thorough discussion of the various rounds and their abilities, but it also is humorous.
My Son had just purchased a new motorcycle, and within hours, he has dumped it, some cosmetic damage to the bike, and some new areas of pavement rash on him, but he told me of a large black dog which had rushed him up the street, and caused him to wreck. At first I thought he was attempting to blame his misfortune on other than his own actions, but later began to believe him. After a while, I went into the bathroom, finished emptying a small plastic bottle of vitalis hair oil, rinsed out the bottle, and refilled it with ammonia. Put the small 3 ounce bottle in my jacket pocket, and took his bike to check out his claim. Sure enough, a very large dog almost able to look me eye to eye ran at me, and I gave him a very good shot of the ammonia, right in his wide open mouth, eyes, nostrils, at a distance of 3 or 4 feet. Immediate end of attack, and I returned back home, refilled the little bottle, told the Son to carry it with him.
While we are talking about this, the door bell rang, and the dog's owner is there extremely upset concerning his dog, was going to "whip my ass", and other not pleasant actions. I reached over, took the bottle of amonia, and gave him a shot of it, and he fell off of my stoop, but did make it home. Neither he or the dog was ever a problem after that, as the dog would run and hide in the back yard when he heard a motorcycle comming after that. There was a "lease law" in affect, but he had chosen to ignore it, with both he and his dog learning to respect other's rights to use the public streets.
BTW, I would of had severe legal problems if I had of shot the dog.
Several years later, one Sunday morning before dayligt,I went down to my paper box to get my Sunday paper, and was braced and menanced by two large dogs. I had a .22 mag derringer in my pocket, and drew, shot th elargest from a distance of maybe 4 feet, and he didn't make any more moves. The other one ran off, and lights began to come on around the area. Next door neighbor came out all upset, saw a dead dog laying in my drive way, with a stream of blood running from the single entrance hole in the skull, and backed off. Still have no idea who owned that absolutely beutifal collie, but it now was dead. Owners have more responsibility to control their pets, but too many do not do so.