Single shot shotguns are generally the least expensive; their downfall is that they only hold one shell at a time. To fire again, you have to open the breach and insert a new shell, a time consuming activity. Still, they are a functional tool for many tasks.

    Pump-action shotguns are the most common kind. They are known for their low cost (though some models can still get very expensive, they are some of the cheapest common shotguns), and reliability. After every shot you must pump the fore-end (place where you put your left hand) of the gun to eject the spent shell and load another from the magazine tube into the chamber.

    Auto-loader shotguns (also known as "semi-automatic") use a few different types of systems so the only operation you do to fire a round is pull the trigger. Reliability is lowered and using a variety of rounds reduces reliability even more.

    Double barrel shotguns come in two varieties: over-unders (O/U) with one barrel above another, and side-by-sides, in which the barrels are located horizontally. Some people prefer one style, some the other; neither is ultimately better, and both styles are expensive.

Barrel length primarily affects the handling capabilities of the shotgun. It also affects the ability to aim the shotgun accurately.

      Longer barrels swing more smoothly and are considered better for predictable targets. Shorter barrels are both easier to maneuver in restricted spaces and are quicker to point; they are considered better for combat or unpredictable birds.

      Longer barrels give you a longer distance from the end of the barrel to your eye, making eye alignment less critical. This makes them more accurate.

      There is a slight increase in muzzle velocity with longer barrels, but it's not enough to worry about. More important is the increased flash and noise when shooting a shotgun with a short barrel.

    choke is a section at the end of the barrel which slightly constricts the diameter of the muzzle. For shot, it makes the pattern tighter, and travel further while maintaining a dense enough pattern to kill/destroy your target. There are many sizes of chokes, and a couple types of chokes which may be in a barrel.

      The size of the choke changes how wide the spread of the pellets will be. The tighter the choke, generally, the tighter the pattern. Loose patterns allow for greater aiming error, but it also means that your range is more limited.

      The two types of chokes are fixed chokes and screw-in chokes. Fixed chokes are part of the barrel design and cannot be changed or removed (without major work). The screw-in choke means the end of the barrel is threaded (inside the bore) to allow many different sizes of chokes to be easily replaced.

      Slugs and buckshot should not be shot through both tight (improved modified, full, or extra full) fixed chokes or any type of screw-in choke; you are likely to damage the gun.

    Some shotgun barrels are rifled. These are much less versatile than most shotguns, not being able to shoot bird-shot, buckshot, or normal slugs, but are very accurate when shooting sabot slugs.

Generally, shotguns are able to shoot two types of ammunition: single large pellets called 'slugs', which make the shotgun act a bit like a rifle, and shells full of smaller pellets called shot, which is useful for hitting small/moving targets.

    Higher shot numbers indicate smaller size shot; #9 shot bird-shot is much smaller than #4. This applies to all 'categories' of shot.

      One category of shot is bird-shot, used to hunt birds or shoot targets. The most common size, #7 1/2, is about .1" in diameter.

      The other category is buckshot, generally used to hunt large critters such as coyotes or deer. In such a load, pellets as large as .38" are carefully packed into a shotgun shell.

    Shotgun shells are available in either high-base (AKA high-brass) or low-base loadings. The high-base shells have more powder and are thus more powerful - use them when you need something extra.

    A shotgun shells come in various lengths. In 12ga, for instance, common lengths are 2.75", 3", and 3.5". A shotgun can shoot shells shorter than it's chamber (which will be marked on the barrel), but not longer. Longer shells have more pellets and more powder... and generate much more recoil. You'll only want to used them when you have to.

    Bore size is also a big consideration as 12-, or even 10-, gauge shotguns can be painful to shoot for some (untrained, sensitive, small, or weak) users. 16, 20, 28 gauge, or .410" shotguns are available which have much less kick and thus are easier to handle for such individuals.

    Slugs are useful for hunting large animals at moderate ranges.

    • Don't fire slugs through tight chokes.

      Don't shoot slugs through "over-bored" barrels.

      Sabot slugs won't preform well in smooth-bore (unrifled) barrels. Use them in rifled barrels.

      "Rifled" slugs are designed to be used in smooth-bore barrels.

    The patterning board is your best friend for figuring out what ammo your shotgun likes and how various chokes work in it: simply shoot once at a piece of paper and look at the resulting pattern.