Not many people will survive TSHTF if firefights are a big part of it. The reasons are numerous. Here are a few:
-Most people have no actual combat experience. What you think and hope you'll do in combat is usually very different from what you will actually do.
Watching combat on TV from the comfort of your couch in a warm house, pausing once in a while to grab another beer might have misled you as to how it actually feels like to be under fire in a cold, dark place, scared ####less. Many people don't have the will to return fire when someone shoots at them.
If you have never been shot at with intent, you have never experienced paralyzing terror. That fear usually removes a person's capacity to do anything else other then cower or run.
You've heard about the "fight or flight" instincts that are hard wired into our brains; most of us react with the "flight" part of it.
You won't know who you're fighting, how strong they are, what their strategy is, etc.
All those factors will either get you killed really fast or will take the will to fight right out of you, especially if you have women and kids with you.
- You have no means to resupply once you've burned through your ammo.
Two, three thousand rounds of ammo is nothing if you are engaged in a steady firefight; you can burn that up in a matter of a few short hours or less.
-You have no medical support.
The smallest gun wound could spell your death (be it fast or slow) if you don't have it taken care off by someone who knows what they're doing, in sanitary conditions.
The S will HTF sooner or later but on a scale from "1" to "10", where at "1" everyone bunkers down in their house playing video games and eating Kraft Dinner and at "10" the bikers from The Road Warrior have surrounded your house , I think a "4" or a "5" is the max will see around these parts of the world.
If there is civil unrest, it will be directed mostly at the government, in the form of demonstrations and riots and they will be contained in certain areas.
Crime will most likely take a turn for the worse, but at that point you will have your doors and windows fortified a bit and a firearm on hand in your house, just in case.
Human society has a natural tendency to maintain a basic social structure even in the worst of times so I doubt that neighbors will start shooting each other.
The main reasons to own firearms when TSHTF are, in no particular order, these: deterrence, basic home defense against desperate small time robbers, hunting and ensuring your safety when traveling through bad spots.
You might never get to shoot your guns, or if you do it will most likely be into the air so an AR 15 will be just as good when TSHTF as an SKS.
The main benefit of owning any gun will be a boost to your self confidence.
Have water, have food, have guns. No mater what happens, you will not be worse off by having them.