The right of self defense is a basic right inherent to all creatures. You defend yourself and your family with whatever means is needed to get the job done. If than means using a shotgun on someone wielding a baseball bat, so be it.
Not in Britain, not anymore in an effective way. You cannot carry a weapon with you.
If you are targeted by multiple assailants, or people bigger, younger, tougher - well too bad, so sad.
The State’s desire for a disarmed population trumps all else.