Shotgun

The Shotgun is an ancient Imperial weapon, much the same as the Heavy Stubber, which fires solid slugs that burst into submunitions to spread out over a wider area. Most Guardsmen that use the shotgun prefer the double-barreled version, and its reliability makes it the mainstay of the Elysian Drop Troopers, who prefer it over the Lasgun when entering hostile drop zones. The Adeptus Arbites also use the shotgun for crowd control and urban conditions and have developed special 'Executioner' shells for them. Space Marine Scouts are also known to use shotguns during their missions.

Shotguns are commonly used by criminal lowlifes in the lawless regions of most hive cities, where a large variety of specialist ammunition is used, including man-stopper rounds, modified bolt rounds and incendiary shells.

Imperial Navy starships carry shotguns for the crew to use during the rare boarding actions or, more frequently, against uprisings by the often mistreated crewmen aboard the ship. These particular shotguns fire shells made specifically for combat aboard a spacecraft - the shells are packed with twists of metal wire and shards of broken glass, ensuring that a shot will shred soft flesh at close range, but will not puncture the ship's hull.

Shotgun Variants

 * Astartes Assault Shotgun - While not as iconic or widespread amongst Space Marines as the Astartes Bolter, the Astartes Assault Shotgun is a powerful and versatile weapon used by their Scouts. These bulky, clipped shotguns can fire in single shots and in both semi- and fully automatic modes, and can use an array of specialty ammunition ranging from armour-piercing penetrator rounds to the powerful manstopper rounds. Assault shotguns are best used in urban and close-quarters combat, as well as in boarding actions aboard voidships.
 * Cypra Mundi "Ironclaw" Shotgun - These standard shipboard weapons are designed to resist the rigors of the void and have a reinforced, weighted stock, which can double as a club if needed. Storage lockers filled with Ironclaws are commonplace on military vessels and unlock automatically to arm the crew when the signal is given to repel boarders.
 * "Raven Pattern" Shotgun - Raven Guard Scout Marines are among the best reconnaissance units the Adeptus Astartes has to offer, forging ahead of the rest of their Chapters warriors, identifying targets for quick strikes and disrupting enemy logistics. For this reason, Raven Guard serving in the Jericho Reach Deathwatch are commonly deployed to strike missions in the Canis Salient, using their stealth to operate behind enemy lines and strike high value Tau targets. During a recent strike mission, shotgun fire gave away a scout’s position and compromised the entire mission. In response, Deathwatch Forge Master Harl Greyweaver used an ancient technique incorporating flash and sound suppressors into the scout’s muzzle (a long black cylinder attached to the weapon’s barrel) making it completely silent when fired, without reducing damage or the ability to make use of variant forms of ammo. This modification was met with such great success that Greyweaver is willing to provide his time and skill to any Raven Guard who has proven himself worthy of the upgrade.
 * Shotcannon - A Shotcannon is essentially a cross between a Shotgun and an Autopistol: it is a short-barelled Shotgun with a very rugged and slightly more complex firing mechanism allowing it to fire on fully automatic mode with a high rate of fire. The Shotcannon is fed from a large drumbox clip containing over fifty shells, allowing for prolonged bursts, and a short burst of a half-dozen shells at point-blank range can easily shred anything not protected by some form of Power Armour. The weapon is favoured by Imperial Navy Naval Armsmen and boarding parties despite the weapon's powerful recoil and the very limited effective range because its impressive firepower at close range is perfectly suited to combat inside cramped corridors that are a staple of voidship boarding actions.
 * Shotgun Pistol - Compact single shot hand cannon, designed to fire shotgun cartridges. These weapons are often the preferred sidearm of petty officers and bosuns who carry them to discourage any thoughts of mutiny, earning the weapon the nickname of "persuaders" in Naval slang.
 * "Vox Legi-Pattern" Arbites Combat Shotgun - The primary weapon of the Adeptus Arbites is the combat shotgun. It is valued for its stopping power, simplicity, reliability, and for its ability to intimidate. Even the most dusty, ancient Judge haunting the Halls of Judgement on Terra will have cut his teeth on the brutally effective shotgun drills which form the foundation of all Arbites combat training. A large variety of different shotgun patterns are used in different Arbites Precinct Fortresses across the galaxy, depending upon the proximity of the local Forge Worlds. The Vox Legi-Pattern is particularly widespread amongst the Arbitrators of The Periphery, and is broadly typical of the weapons favoured by the Arbitrators of the Calixis Sector. Effectively a large-bore, locally manufactured version of the shotgun designs used by many planetary enforcers, the Vox Legi is a devastating and adaptable weapon that fires shotgun shells nearly the size of those employed by the Adeptus Astartes. The increased size of the weapon reduces its ammunition capacity compared to that of other shotguns, but it still remains more powerful and adaptable than a standard shotgun. Most patrolling Arbitrators take advantage of this flexibility by carrying a variety of shotgun shell types so that they can employ different tactical options. Over-engineered by a considerable margin, the weapon is also perfectly capable of being used as a large club -- indeed, it is expressly designed with this secondary purpose in mind. It is also designed for maximum psychological impact, with a very audible pump action (standard Arbites riot training makes use of this). The sound of a hundred Arbitrators simultaneously chambering their weapons has ended countless riots in a single instant over the millennia.

Shotgun Ammunition
While not as lethal as regular rounds, a volley excels at frightening off most enemies. As they can also be used in standard shotguns, they offer excellent tactical flexibility without the need for specialised flamer weapons. The duration of the discharge means it can only be used in single-shot mode.
 * Ignitius Shotgun Shells - These shells are packed with pyrotechnic materials, so when fired a huge gout of flame is produced for several seconds.