A) You are on a bus and a guy starts shooting passengers. You have no gun. What do you do?
B) You are on a bus and a guy starts shooting passengers. You have a gun. What do you do?
I'd respond exactly as you say you would. Except for the lobbying part. I have already been a part of a successful lobby in my state for carry laws. The laws in other states I'll leave up to it's citizens.
You left one possibility out.
C) You are on a bus and a guy with a handgun, that's not foaming at the mouth, demands a purse from a little old lady. What do you do?