If somebody really wants to shoot and kill you they will. Just because you have a gun doesn't mean you can stop that first shot. How many armed policemen have you heard of being shot to death? I mean that is a guy with his gun on the outside with ready access and with that uniform he is always in code red. Even he can't stop that first shot. True he may get a shot at that perp if he is not totally out of commission.
Am not putting guns down. Someday I may get a pistol but for now I have a shotgun in my bedroom. But when I am out on the street I only carry a razor knife.