The problem with a taser, or a cattle prod, is that the electricity goes through the bad dog and into the one he/she is biting, your dog. Be sure to zap when they're disconnected.

BBs on a big dog just piss them off, as will any light gauge weapon. Aside from getting their attention (and if that's all you needed to do your voice would work as well) they do little good. A fairly powerful pellet gun sometimes works, and firecrackers (although they're slow to use in an emergency). Living on an Indian reservation we have rifles and shotguns, but that's just not practical in urban areas. Anyhow, you need the weapon that works, and that's situational and practical.

As for the police, get to the vet if you're going to press charges, otherwise play it by ear. Courts like proofs and substantiation or they tend to do nothing. You could win a claim even against people without means and get a settlement, which they would then have to pay for with time in jail, and the dogs could be euthanized. Personally, I don't trust pit bulls, nor pit bull owners. Who would want an animal bred specifically to kill or maim another animal.

Glad to hear your dog is healing, it really sucks when they end up dead, I know, someone poured gas down the throat of my dog when I was about 6 years old. She ran up to me and laid at my feet frothing at the mouth, and died. I'll never forget, nor forgive.