A shotgun is a shoulder-fired firearm that fires a number of small spherical pellets (known as shot) or a solid bullet (known as slug). Shotguns come in a range of calibres and operating mechanisms. These are very popular with law and enforcement agencies and civilians for hunting and sporting purposes.The barrel of the shotgun is not rifled i.e. it is a smooth bore. Due to this shotguns are not accurate and have lower ranges. After the advent of rifles, shotguns lost their popularity. However, shotguns proved to be very useful in trench warfare during the First World War and thus their popularity and use saw a revival. Since then, shotguns are being used in a variety of roles by civilians, law enforcement agents and military personnel.When the shotgun is fired, the energy of the exploding propellant gets distributed across the pellets and so the stopping power of each pellet is very low. This makes the shotgun very useful in hunting smaller game such as fowl. However, when fired a close ranges, the shotgun offers a large stopping power albeit low penetration. Since the pellets spread out over an area, the shotgun has to be pointed only approximately at the target to make a hit.Many different types of shotguns have been designed. They range from small sized shotguns to massive punt guns. In addition, shotguns operating almost on every firing mechanism are available. Shotgun designs are unique on the basis of the firing shot. The shotgun shell is usually short, wide, with straight walls and operates on low pressure when compared to assault rifle rounds.Shotgun ammunition is commonly known as shells, shot shells or shotgun shells in the United States. In the United Kingdom, there are called "cartridges". Shotguns are also known as pepper guns and scatter guns.Shotguns are typically used against small and moving targets. Since the pellets of the gun spread over an area, the gun has to be aimed only approximately at the target. However, shotguns are not accurate over longer distances. In addition, they also lose penetration power with distance. Shotgun ammunition which have lesser number of pellets or a single slug have higher penetrating power but at the expense of lower probability of hitting the target.Shotguns offer a number of advantages over other handguns and rifles. First and foremost, the shotgun offers tremendous stopping power at shorter ranges. Secondly, it is easier to aim which makes it very easy to be used by an inexperienced firer. Thirdly, it causes multiple wounds to the target which will disable him/her instantly. Additionally, shotgun pellets cannot penetrate walls reducing the chances of hitting bystanders. Due to these reasons, law enforcement agencies across the globe prefer to use shotguns.

The Heckler & Koch CAWS is a bullpup automatic shotgun designed by Heckler & Koch in collaboration with Winchester/Olin in 1980s. “CAWS” stands for “Close Assault Weapon System”. In the later years the CAWS project was canceled.

The development of the CAWS started in the early 1980s with the aim of created the next generation personal firearm. The CAWS was intended to have high power firing capabilities and an effective range of 100 to 150 meters. Heckler & Koch developed the weapon while Winchester/Olin was responsible for designed the ammunition.

The design of the CAWS draws heavily from the earlier G11. The CAWS feeds from a 10-round magazine. Each round contains 20 flechettes or 8 tungsten alloy pellets. The shotgun also comes equipped with telescopic optics. One of the interesting features of the CAWS is its very light recoil.

The CAWS project has been cancelled and remains only a demonstrator project. However, it shows the level to which a shotgun can be taken. It displays how a single gun can be used to fire different ammunition types. By changing the magazine in a near futuristic shotgun, it may be possible to fire miniature grenades, penetrating rounds or standard anti-personnel ammunition. A shotgun of this capability will definitely find market in the very near future.

The Franchi SPAS 15 is a rifle-style combat shotgun manufactured by Franchi S.p.A, an Italian firearms company. The shotgun is not designed for fully-automatic firing but is still a military combat weapon. In appearance, it resembles an assault rifle with a 10-round magazine and a foldable stock. The design is highly innovative for a shotgun.

The SPAS 15 is based on the earlier SPAS 12 and has similar construction. However, it differs in the feed mechanism. Unlike SPAS 12, it uses a detachable box magazine with 10-round capacity.

The SPAS 15 has enjoyed significant mainstream adoption. Law enforcement agencies in several countries have adopted the SPAS 15. In addition, it is also being used by the Italian Military.

In the United States, it is very rare to find a Franchi SPAS 15 as its import has been made illegal. However, it is possible to legally own and sell a SPAS 15.

The SPAS 15’s design is highly innovative. It combines the elements of two completely different weapon systems. It can be said that the SPAS 15 represents a intermediary step in the shotgun’s progress towards being a military weapon.

The Pancor Jackhammer is a gas operated automatic shotgun designed by Pancor Corporation in the 1980s. There are very few fully-automatic shotguns with the Jackhammer being one of them. It never entered mainstream production and no countries ever adopted it. In fact, according to some sources only two working prototypes of the Jackhammer were ever built. Subsequently, Pancor Corporation went bankrupt and the patents and production rights were sold off.

The Jackhammer was designed and developed by John Anderson. Initially, a number of countries showed interest in the shotgun because of its innovative design. The shotgun was held up for testing by the United States Department of Defence which didn’t find the shotgun to be appropriate and rejected it. During the testing process, Pancor couldn’t obtain export license to fulfil the orders placed by other countries.  Subsequently, the company went bankrupt and its assets which included the initial prototypes had to be sold off.

Design wise, the Jackhammer is a leap into the future. It has a bull-pup configuration and is capable of full-automatic fire. It is designed to use 70mm 12-gauge ammunition fed from a 10-round ammunition cassette which can be replaced just like a rifle magazine. The ammunition magazine also doubles up as an anti-personnel mine when used with a detonator.

Though the Jackhammer never entered mainstream use, it is nevertheless very famous popular-culture. Many video games and television programs often portray it for its futuristic design.

The Striker (other designations: Armsel Striker, Proecta Bulldog or Cobray Street Sweeper) is a double-action shotgun developed by Hilton Walker in South Africa. It features a rotary cylinder-type magazine and a carbine type receiver and is overall a very good shotgun.

The Striker has a foldable stock and feeds from a 12-round rum magazine located in front of the trigger assembly. In addition, it also has two pistol grips which make it easy to be controlled during firing.

The construction of the weapon is very robust and simple. Several law enforcement agencies across the globe have adopted the Striker for various purposes.

The initial versions of the Striker had many design flaws. It was found to have slow and a cumbersome firing mechanism. In addition, the drum had to be wound back after loading for the shotgun to be fired. However, many of these flaws were corrected in the subsequent models.

The Striker is unique among shotguns in terms of design. Its balance and layout make it an exceptional weapon. However, the wide drum means it can be difficult to conceal which, advantageously, makes it a bad choice for use by criminals.

In the United States, it is very difficult to find the Striker. There are regulations on its import as it has been labelled as a destructive weapon by the ATF. In Canada, it is illegal for a civilian to possess the Striker.

The Franchi SPAS 12 is a shotgun designed and manufactured by Franchi S.p.A, an Italian firearms manufacturer. The shotgun was manufactured from 1979 till 2000 and is used by a number of countries such as Ireland, France, Taiwan and Thailand.

The SPAS 12 is designed as a combat shotgun for use by military and law enforcement agencies. It operates in both semi-automatic and pump-action modes. In the semi-automatic mode, the shotgun can fire 4 rounds per minute with each round requiring the trigger to be pulled once. The shotgun is fired in pump-action mode when low-pressure ammunition like tear gas canisters or bean bags is to be fired.

The shotgun feeds from a seven-round internal magazine. In addition to the magazine, the shotgun also has a cut-off feature which allows a round to be introduced directly into the chamber while loading.

The SPAS 12 has a spread of 900 mm at 40 meters. Because of the wide spreading of buckshot, the shotgun can be aimed roughly at the target to hit it. The shotgun’s spread can also be varied by using an attachment known as the “spreader”. In addition, the shotgun can also be mounted with a grenade launcher for additional firepower in the field.

The SPAS 12’s stock had a shoulder hook which enables the user to fire the weapon with a single hand. However, in practice this is not so easy and requires great strength on the part of the user. The shotgun is considerably heavy and at the same time the 12 gauge round has high recoil.

The Ithaca Model 37 is a pump-action shotgun designed for use by civilians, law enforcement agencies and the military. Large numbers of these shotguns have been manufactured since production started in 1937. The Model 37 was designed by John Browning and John Pedersen in 1933.

After the First World War, Ithaca began to search for a shotgun to compete with the Winchester Model 12. Ithaca selected the Remington Model 17—the patents of which were to expire in 1933 and thus named the shotgun as Ithaca Model 33. However, later on it was discovered that the patents held by Pedersen didn’t expire until 1937 and thus the shotgun was re-designated as Ithaca Model 37.

There are two variants of the Model 37. These are the ‘M’ (Military) and ‘P’ (Police). Both these versions were excellent at close-range combat. Subsequently, these models were used to design the Ithaca LAPD shotgun which was designed specifically for use by law enforcement agencies.

One of the largest users of the Model 37 is the Los Angeles Police Department. The Model 37 is also used by civilians for sport and self-protection. However, the use of the Model 37 is on decline because of low availability and increasing costs. Chinese copies of the Model 37 are also becoming popular in the United States which is leading to a further decline in sales of the original gun.

Variants of Ithaca Model 37:

The Ithaca 37 has been the basis of several variants. Some of the popular variants include:

>> Deerslayer: Variant with a shorter barrel and rifle aiming system.

>> Ultralite: Lighter variant with aluminium body.

>> DSPS: A variant of the Deerslayer shotgun designed for military and police use.

>> Stakeout: Variant with 13 inch barrel and pistol grip.

>> 28 Gauge: Variant designed to fire 28 gauge ammunition.

The Beretta RS 202-M2 is a pump-action shotgun manufactured and distributed by the Italian firearm manufacturing company—Fabbrica d'Armi Pietro Beretta. The shotgun feeds from a six-round tube magazine and features a conventional design.

The RS 202-M2 is one of most dependable pump-action shotguns. It takes advantage of Beretta’s experience and expertise acquired in manufacturing more than a million automatic shotguns.

The Beretta RS 202P features a foldable metal stock and a perforated shroud around the barrel. However, internally its design is very conventional and doesn’t differ much from other shotguns in its class. The RS 202 can also use 8-round magazines designed by Valtro—another Italian firearms manufacturer.

The shotgun can also be mounted with aiming optics. The top of the receiver has rails for mounting aiming scopes. In addition, the shotgun’s pistol grip makes wielding the weapon very comfortable during firing.

The main advantage with the Beretta RS 202 is that it can fire a range of ammunition types. In addition, it also has a variable choke and a shot expander that allows the firer to alter the spread of buckshot fired by the shotgun.

The Mossberg ATPS 500 is a pump-action shotgun designed and manufactured by O.F. Mossberg & Sons since 1960. Other shotguns in the same series as the Mossberg 500 include the 590, the 505 and the 535.

The Mossberg 500 has a conventional design without any advanced design features. It is available in civilian, military and security variants. All of these versions have the same basic design, except for a few changes.

The shotgun is designed to fire the 12 gauge round. However, versions for the 20 gauge round and the .410 bore ammunition have also been designed. The shotgun feeds from a six-round tubular magazine and has very good firepower.

The Mossberg 500 was designed primarily as a military weapon. This becomes evident from the inbuilt bayonet mounting and rails for mounting optical scopes. The shotgun can also fire solid ammunition. However, since the barrel has no rifling, it may not be accurate for long distances.

The Mossberg 500 has a long history of service with the United States armed forces. It continues to be in service with various branches of the US military. In 1999, the US Army officially adopted the M1014 Combat Shotgun. However, it continues to use the Mossberg 500 and new orders continue to be placed.

Variants of the Mossberg ATPS 500:

>> Field Models: These are designed for sporting and hunting. These come in a variety of barrel lengths and furniture. Some versions also have rifled barrels.

>> Special purpose Models: These are for self-defence, police use and for use by the military. These have shorter barrels and some versions come with pistol grips for better handling.

>> Law enforcement Models: These have heavier barrels, metal safeties and trigger guards. These are designed to pass stringent requirements of the US Army and are more robust.

>> Home security Models: These are designed for .410 ammunition and are designed for defensive use. These models are designed for the novice user who doesn’t have much experience with firearms and yet has to use one to defend himself/herself.

The Remington M870 is a pump-action shotgun designed by L. Ray Crittendon, Phillip Haskell, Ellis Hailston, and G.E. Pinckney and manufactured by the Remington Arms Company Inc. It is widely used by civilians for target practice and hunting. In addition, it is also used by law enforcement agencies for riot control and by the military.

The M870 is a 12 gauge shotgun and feeds from a seven-round tubular magazine located under the barrel. Subsequently, other versions for 16, 20 and 28 gauge were also developed. Versions with variable barrel lengths were also designed. The P variant of the M870 has a foldable metal stock.

The M870 is primarily designed for close-quarter combat. Its pistol grip makes it very easy to aim and fire in close-combat situations. In addition, it also has a very high stopping power to intimidate even the toughest of the attacker.

The M870 is comparatively a costly weapon. However, it is one of most popular shotguns to be ever manufactured. Till date, more than four million units of the M870 have been sold. It holds the record of the best selling shotgun is history.

Several other shotguns have been designed on the basis of the M870. These can be broadly classified as under:

>> Wingmaster: These models come with polished wood furnishings and blued steel body.

>> Express: These models come with satin wood or synthetic furniture and bead-blasted steel body.

>> Marine: These models come with synthetic furniture and nickel-coated steel body.

>> Police: These models come with wooden or synthetic furniture and high lustre steel body.

The Winchester Model 12 is a pump-action shotgun designed by John Browning and Thomas Crosley Johnson. It was manufactured by the Winchester Repeating Arms Company from 1912 to 1963. Some special versions were manufactured until 2006. More than 2 million Model 12 shotguns have been manufactured till date.

The Winchester Model 12’s design is based on an earlier shotgun known as the Model 1897 ‘Trench Gun’. This weapon was used extensively in the First World War in close-combat situations in the trenches. However, it proved to be lacking in many regards. Thus the Model 12, developed in the meantime, was immediately adopted after the end of the war.

The Model 12 had several features that were very similar to its predecessor. For example, the Model 12 retained the Trench Gun’s bayonet lug though it was rarely used. The Model 12 saw extensive action throughout the Second World War and remained in service with the US Military until the 1960s.

The Model 12 came in different versions with different bores and barrel lengths. Versions were designed to fire 12, 16, 20 and 28 gauge shells. The Model 12 fed from a 5-round tubular magazine.

During the First World War, the US Army purchased 20,000 Model 12 shotguns and during the Second World War another 80,000 were purchased and deployed mainly in the Pacific Theatre. In addition, riot-control versions of the Model 12 were also purchased for protecting bases. The shotgun was also deployed during the Korean War and in Vietnam. Subsequently, when the Model 12 was discontinued in 1963, the Ithaca 37 took its place.