If you ever visit a survivalist or prepper forum, one of the first and most prolific threads will probably be the "AR vs. AK" debate. Let's just say that there are a lot of gun nuts in the prepper community. In case you are unfamiliar with firearms, the AR-15 and AK-47 are semi-automatic rifles primarily designed for shooting people and are not as practical when used for anything else.
Now, I believe that firearms can be an important part of survival planning. They're useful for hunting game and to keep yourself from becoming a victim in the craziness surrounding an emergency situation. You could be planning and storing for years, then have it all taken away in an instant by the guy next door who's never prepped a day in his life but inherited a dusty revolver from his grandpa.
That's a possibility, to be sure.
But how likely is that? Like everything else in life, raiding is a risk vs reward question. For someone to wave a gun around and intimidate people out of their supplies would mean that there is little or no law (low risk) and they need those supplies (high reward).
So, for raiding to be a realistic concern there would basically have to be a collapse on a massive scale for an extended period of time. People are starving and there isn't anyone to enforce the rule of law. Probably 99.999% of emergency scenarios that's not going to happen. If there's an earthquake or flooding than within a fairly short period of time there will be an emergency response from the Federal and State governments (most of the time, obviously things like hurricane "Katrina" were not handled well). Most of the time there will be National Guardsmen and emergency workers there within 72 hours and they will be providing food and clean water.
That means a guy waving a gun to take your supplies can be arrested by guardsmen or police (high-medium risk) for supplies that are in excess to what is needed to simply survive (low reward).
That means that in most scenarios the "AR vs AK" debate is a moot point. They can be used for hunting small to medium sized game but that's not what they were made for. They use fairly small rounds, low recoil, with the intent to rapidly fire a lot of accurate shots at a short distance. For them to be a 'practical' survival tool then they would be used against people, like they were designed. Otherwise, having bolt action hunting rifle would be by far the smarter choice (and a lot cheaper).
That said, if the situation is so bad that raiding is happening, having a fire arm is a quick way to change the risk vs reward question. A guy waves a gun at you and you pull out yours, suddenly taking your supplies is a high risk prospect. Imagine you're starving, you break into a house, and hear someone in the darkness rack a shotgun. You'd run like hell back the way you came.
That's something else to keep in mind, becoming a 'raider' is not something that most people would be able to do easily. We're not wired that way. We don't walk around hurting each other, on the contrary, we often times go out of our way to help each other. So, after decades of working together, helping each other, it's not like something bad happens and we suddenly turn into homicidal maniacs. Maybe you you have a closet, Mad-Max wannabe in your neighborhood, but the vast majority of us are average joe's just trying to get by.
Maybe you have a local gang that looks pretty shady. When something bad happens are they going to grab some guns and immediately start taking over? Or are they going to run home and check on their family? Make sure their parents and siblings are ok? They are people too and will react the way that most of the population does.
Emergencies don't lead to desperate measures, desperation leads to desperate measures. Under normal circumstances that means that they guy breaking into your house probably has a 'desperate' need for money or drugs. When there is some sort of the disaster it might mean that the guy breaking into your house has two starving kids he's trying to feed. Keep that in mind and maybe offer him a few MREs before you bust out your AK.