This sounds like a good option...and makes you look better for attempting a less than deadly option first. I'm a strong 2a proponent, but using a firearm should always be a last resort to protect yourself from death/serious bodily injury. I believe you are totally in the right to protect yourself, but law enforcement and the lawyers would have fun with this and make your life hell after the fact, as you don't HAVE to ride your bike past those dogs, you knew they were there and that you knew there would be a confrontation.....therefore it was an avoidable situation and shooting was not your last resort. The case could be made that you actually rode into the situation intending to shoot the dogs. Should this story make the media and they put their own spin on the story, are you ready for the barrage of hate from the animal lovers? The bottom line is to always consider all possible outcomes before using a firearm.