Guns are a very hot topic on both sides of the fence. If you decide not to own and use one that is your decision, but in a true survival scenario they could make the difference. Whether it be for defense, hunting, or, in the worst case, offense, they are a tool like any other. Also like a tool, there is no one perfect one for every problem. For example, a screwdriver might take the place of a hammer, but is a very poor substitute. In the same way the wrong gun may work based on what situation you face, but it may leave less than desirable outcomes.
To start at the beginning, there are 3 basic categories of guns. There are handguns, rifles, and shotguns. Each of these has its advantages and its disadvantages. For the sake of this post, we will only cover typical types of guns. There are many odd types of guns out there, but they do not really fit our needs. Also, aside from a total end of society scenario, machine guns are not going to be an option like the movies want to depict. They are available, but expensive, hard to obtain, and come with many restrictions.
Handguns are normally the smallest size of the three types. They can be semi-automatic with detachable magazines or be a revolver with a re-loadable attached cylinder. The detachable magazines can make them fast to reload, but generally they use a smaller size bullet that is less powerful that a rifle. Handguns can be good for shorter distance defense but rapidly loose effectiveness beyond a certain distance. This distance varies based on the caliber of the bullet. Most handguns are not suited for hunting except in a pinch. The effective range and smaller caliber can make it harder for larger game. For smaller game like squirrels or rabbits, smaller calibers can be used, but the shorter barrel will make it harder to be accurate even at moderate distances. As with the screwdriver/hammer example, they can be used, but will not perform as well as other options. In all reality, handguns are best suited to the role of self-protection. They can be concealed easily and weigh less than a rifle or shotgun.
Rifles come in various lengths and calibers. They can be single shot, semi-automatic, bolt action, or pump. They can have detachable magazines, affixed tube magazines, or non-removable internal magazines. The longer length makes them more accurate over longer distances than handguns. The wide variety of calibers means that you can find one to deal with anything from small game to large predators (both 2 and 4 legged variety). These still do have the issue that normally each can only fire one caliber. So at times you might find that that caliber is too small or too large for you intended prey. It is almost impossible to conceal a rifle on your person unless you want to wear a parka or trenchcoat. This can create issues in a chaotic environment. Law enforcement may be trying to confiscate guns to help keep order or devious individuals may see an opportunity to further arm themselves by waylaying you. Rifles range from older military surplus like bolt action Mosin Nagants, to hunting rifles, to semiautomatic AR-15s and AK47s.
Shotguns are also longer than pistols. They can be single shot, semi-automatic, bolt action, or pump. Normally, unless single shot, they have a tube magazine connected below the barrel, but a few do have detachable magazines. Shotguns can have different barrel setups to make them more accurate over longer ranges, but their range is still much shorter than a rifle. In contrast though, shotguns can use many types of shells. These can range from a bunch of shot in increasingly larger sizes up to a solid lead slug, The shot size can be chosen to match the prey you are hunting. This allows you to hunt a much larger range of prey by simple swapping the type of shell. Smaller size shot can be used for small game like rabbits and then the largest size shot (call buckshot) or slugs can be used for larger prey like deer. There are different sizes of shotguns called gauges with the lowest number being the biggest gun. 12ga is the largest common size and is on the larger end of the sizes. One downfall of a shotgun is that it does have a significant recoil that you will have to train to deal with. If a 12ga is too much you can move down to a 20ga or even a .410 (caliber not gauge, too long a story to cover here) which is the smallest size. Each of the smaller sizes still can use various types of shells.
Which gun you chose has to be a person choice. It must be based you your abilities and the scenarios you feel you will face. Overall, there is no ‘perfect’ survival gun. If you plan for survival in the middle of an urban environment you may be more worried about keeping a low profile and defending yourself than hunting large game. A handgun or shorter shotgun can be better concealed and used more easily inside buildings than a long barrel rifle. If you plan to hold up deep in the wilderness, a rifle might allow you to hunt larger game or defend from invaders at a distance. If the terrain there limits distance, a longer barrel shotgun can also be used effectively.
One good way to start making a choice is to visit a professional shooting range. Many of them have guns for rent and are knowledgeable about your areas laws. You can rent some types and sizes to test out for a fairly nominal fee. This will be money well invested in helping you decide on not only a type of gun, but a caliber and model you can be comfortable with. A gun you cannot effectively use can be more of a hindrance than a help. Like all equipment, you need to practice routinely to ensure you and the gun are both ready for action.
Since every scenario cannot be covered by one type of gun, just like your standard tool box, multiple types may be the best answer. It is easier to cover all your needs with a couple of different guns. A combination of one or more will allow you to respond to the disaster you prepared for much more effectively. So take a serious look at your planning. If you are truly honest, some type of gun and proper training could be vital in anything beyond your lowest level of disaster.