If you fear for your life and are not a willing participant and don’t see a way out without using force, you can do that.
Read up on disparity of force.
It’s not something I’d ever encourage someone to want to do, or be excited about doing. But when multiple assailants are facing you and you believe you are in imminent danger and fear dying or permanent bodily injury, you are able to defend yourself. If it’s 4 against one you are at a disadvantage and 4 of them can permanently injure or kill you, so use of the firearm against them is reasonable under disparity of force standards. It is even more warranted if you are old and they are young, if you are disabled, if you are smaller, if you are female and they are male.
What the hell are words on paper going to do for you standing over 4 unarmed dead bodies with a pistol? A corpse can't really confess to planning to mug you now can it?