Shotguns come in both single barrel and double-barrel types. Double-barreled shotguns have two triggers, one to discharge each barrel. Of the double barreled shotguns, there are two types: "side by side" type and "over and under" type. What this means is how the two barrels are positioned. In "side by side" types, the barrels are placed beside one another, whereas "over and under" types have one barrel positioned on top of another.
"Side by Side" type shotgun
"Over and Under" type shotgun
Double barrel shotgun barrels are never attached parallel to each other, but instead set so that their shot will converge at some point (usually at 40 yards distance). In some shotguns, one of the two barrels may be made different from the other. For instance, one may have rifling and the other is smoothbore, or one barrel may be choked for closer shooting. In other cases, both barrels may be made as identical as possible.
Of all the actions, the break-open action, such as the two images above, is the most common type and has been around for a long time. This is a breech-loading mechanism. It was realized in 1875 that the movement of opening the action could also be used to cock the weapon at the same time. The first such cocking mechanism was pioneered by Anson and Deerley for their hammerless shotgun and it is still used almost unchanged to this day. Break-open actions are the most common type used for shotguns.
Another action that was invented in the mid 1800s and rare today, is the side-motion action. In this type of action, the barrels are mounted on the edge of a metal disc. A lever in the bottom of the stock rotates this disc, which causes the barrels to move in an eccentric motion, where they can be reloaded.
Another action that was invented in the 1800s, but is rare now, is the sliding barrel action shotgun. There are only a few manufacturers around that make this type currently and it was never as popular in the 1800s either.
Sliding Barrel Action Shotgun
Lever action shotguns were popular in the 1880s. The Winchester model M1887 was designed by John Browning and became a best-seller for the company. This was the first truly successful model of a repeating shotgun. This action allowed for users to load multiple cartridges into the weapon, not just one or two cartridges. Their popularity waned after the design that we're about to study in the next paragraph was introduced, and we don't see too many lever action shotguns these days.
The action that replaced the lever action design is the pump action shotgun design. The first popular ones of this type were the Winchester M1893 and M1897 models, which were designed by John Browning! It must be noted that when Winchester originally asked Browning to design a repeating shotgun in the 1880s, he had argued that a pump-action mechanism shotgun would be the most appropriate design, but Winchester was a lever-action manufacturing company, so they persuaded him to design a lever-action shotgun, which was the M1887 model described above. However, they did later manufacture his pump-action design as the Winchester model M1893, which was later improved to the model M1897. It must be noted that the M1897 shotgun gained so much popularity that it was used by US soldiers in World War I, where it was found very useful for trench fighting. Its quick shooting speed and massive stopping power made it a very effective weapon for US soldiers to have. In fact, the German troops feared this weapon greatly and the German High Command even attempted to have it outlawed in combat, by citing Geneva convention laws (this coming from the same people that allowed the use of poison gas!). The pump-action shotgun design is still popular to this day.
Pump Action shotgun
There are also semi-automatic shotguns, where some of the force generated by the firing cartridge is used to eject the old cartridge, cock the action and load a new cartridge. Semi-automatic shotguns use a variety of mechanisms: long recoil action, inertia operated action or gas-operated action. The first successful semi-automatic shotgun was the Auto-5 (or A-5) action first designed in 1898 by (surprise, surprise) John Browning! The Auto-5 model remained in production until 1998!
Semi-automatic Remington Model 11 shotgun using long-recoil action
Bolt-action shotguns also exist in the wild, though they are not common. One particular model was manufactured in .410 caliber by the Ishapore arsenal of India, based on the Lee-Enfield SMLE Mark III model.
Ishapore .410 caliber bolt action shotgun. Click on image to enlarge.
In the next post, we will look into more about shotguns.