The mantra of Guns, Bullets, and Beans is a reasonably common one but bullets go both ways. Almost everyone who has served in active duty involving gunshot injuries or has been involved in treating them will tell you never to engage in a fire fight unless you have no other choice. Rather than focusing on building a fortress to defend your supplies it is safer to build a home you can walk away from without compromising your supplies or getting on the wrong end of a gunshot wound.
Rule One: Do not get shot.
Rule Two: Get shot in a leg or arm without any bone involvement.
Rule Three: If you have to be in a fire fight make sure you kill them all before they can return fire.
I have never been shot and I have only had two guns pointed at me but I have nursed a fair number of shot ICU patients over the years. In SHTF things will be different and trauma care for shooting patients (I dislike the term ‘victims’ as it implies powerlessness) needs a hard look at especially if you live in an area of the world that has a lot of armed people around you. This article will have some biology (science is fun!) and I am not talking about body armor or types of ammunition (not my specialty but here are penetration estimates. If Pat uses them there will be graphic photos and I hope these will not trigger anyone but knowledge is power.
The article is long and I am not going into lung, abdominal, brain care as basically you are likely dead. Please look up lung injuries as knowing what tension pneumothorax, septic shock, and paralytic ileus are good ideas.