I would like to provide some advice based on my experience. I have instructed thousands of students in the use of handguns, rifles, shotguns, and machine guns since 1986. My experience with various types of firearms over the years includes owning everything from a silenced .22LR caliber handgun to a Browning .50 caliber belt-fed machine gun.
Many writers emphasize the role of a long gun in hunting to provide food during a survival scenario, with self-defense being a secondary consideration. Let's turn that concept around and discuss what I consider to be the primary importance of firearms; defending your family, group, property, and food.
If you cannot successfully protect what you have, then no amount of collecting food and other essentials for survival will matter if evil people should decide to take your possessions. To successfully protect with your firearm, there are certain requirements that your firearm must fulfill. Your choice in firearms should be based on every factor that will provide you with an edge over the armed bad guys. Otherwise, you lower your abilities and assume more risk. Based on decades of instructional and personal experience, I can provide some advice on what to own and what not to own, and why. I am going to assume you are a novice with little or no training, and infrequent practice experience.