The Storm Bolter is a double-barrelled version of the standard .75 calibre Bolter. As it is heavier and causes more recoil than a normal Bolter, it is even more rarely used than the Bolter by the regiments of the Astra Militarum. Instead, Storm Bolters are the standard weapons employed by Space Marine Terminators or as a pintle-mounted weapon on an Imperial main battle tank. Storm Bolters are also used by the Astartes of the Grey Knights Chapter as a gauntlet-mounted weapon with its feed located on the rear of their armour. The Storm Bolter also sees limited use amongst the Orders Militant of the Adepta Sororitas, where it is considered a specialist weapon, and favoured by those squads of Dominions, the Sororitas' heavy-weapons troops, who prefer to engage in mid-range, anti-infantry combat.
Due to its high munitions consumption, and the lack of dexterity available to the wearer of Terminator Armour, most Storm Bolters are fed from a large box magazine, carrying approximately 100 rounds. These rounds are identical to those fired from Bolt Pistols and Bolters. Before the Storm Bolter was created by the Tech-priests of the Adeptus Mechanicus after the end of the Horus Heresy, Terminators were often equipped with two separate Bolters outfitted with advanced targeting equipment and restricted firing rates to allow them to operate in tandem. These were called Combi-Bolters and they were less effective than the first true Storm Bolter design. They are now only used by the Chaos Space Marines of the Traitor Legions, many of whom still have access only to the pre-Heresy technology.
Known Storm Bolter Patterns
Adeptus Astartes Patterns
- M33 Mark IV - The M33 Mark IV Storm Bolter was commonly mounted on the Mark V Phobos Pattern Land Raiders.
- Mark III Pattern - The Mark III Pattern Storm Bolter was deployed by the Terminators of the Astra Claws during the Badab War.
- Mark IIIc Pattern, Hecaton Variant - The Mark IIIc Variant Pattern Storm Bolter is a standard pattern of the weapon deployed by many Adeptus Astartes Terminators.
- Mark IV Thunderfury Pattern
- Mark VII Pattern
- Mars Pattern
- Incaladion Pattern - The Incaladion Pattern Storm Bolter is known to have been used by Carcharodons Terminators during the Badab War.
- Ryza Pattern - The original Storm weapons arose from experiments in combining different weapons together to achieve greater rates of fire. The Ryza Pattern Storm Bolter links two Bolters to form a single weapon that can shred most foes in a single burst. Rarely seen outside of the Adeptus Astartes, these relic-weapons are typically covered with Imperial scripture and purity seals that speak of their ancient origin.
- Umbra Pattern - The Umbra Pattern represents the standard pattern of Storm Bolter employed by the Terminators of most Chapters of the Adeptus Astartes. Their dual magazines have an ammunition capacity of 40 rounds.
- Ultima Pattern - The Sons of Medusa's Terminators are known to have used Ultima Pattern Storm Bolters during the Badab War.
- Nocturne-Ultima Pattern - A modified version of the Ultima Pattern Storm Bolter used by the Space Marines of the Salamanders Chapter during the Badab War.
Adepta Sororitas Patterns
- Mars Pattern
- Godwyn-De'az Pattern - A common Storm Bolter pattern employed by servants of the Ecclesiarchy. This weapon requires two hands to operate and is essentially two separate Bolters capable of firing in synchronised bursts. Its high rate of ammunition consumption makes the weapon impractical in many situations but few would argue with the results that such a powerful symbol of faith can have upon the enemies of the Emperor.
Adeptus Custodes Patterns
- Lastrum Storm Bolter - The Lastrum Storm Bolter is named for the weaponsmiths of the Lastrum Core Clan of the Appolyne workshops of Terra. Other than being exemplars of their kind in terms of skill of fabrication, they would not be remarkable save for their uniquely powerful ammunition. Rather than the usual Kraken bolts utilised by the Legio Custodes, the artisans of the Lastrum clans hand-manufacture only customised mass-reactive heliothermic warheads for their bolt shells. Once within their target, these burst into brief, but sun-hot incendiary detonations, incinerating their victims from within. These shells are uncommonly dense, requiring a far stronger charge to launch than standard bolts, and only the Lastrum Storm Bolter's uniquely sturdy construction for a weapon of its size can withstand the stress of repeated firing. The sheer resources and artifice skill required to craft these weapons is extraordinary, and as such they could not be mass-produced to arm the Space Marine Legions during the Great Crusade. Even the output of entire generations of the Lastrum clans barely satisfied the demands of the ancient Legio Custodes for the weapons.
Notable Storm Bolters
- Anmael's Reach - During the Jericho Reach's Age of Shadow, many great heroes of the Adeptus Astartes served the Deathwatch and performed deeds that would have been the basis of legend, had there been any to witness their Vigil. One such warrior was Anmael, a Battle-Brother seconded from the Angels of Vengeance. The stubborn drive of his Chapter led him across the Reach in pursuit of countless inhuman foes. Of his last mission, only the Watch Commander and the Chamber of Vigilance of Watch Fortress Erioch know the details, but he was survived by the ornately worked Storm Bolter he bore from his Chapter’s Armoury vaults. It is said that the Anmael's Reach will suffer no wielder less determined than its first, but its fierce Machine Spirit bolsters the worthy.
- Dorn's Arrow - Chapter Master Pedro Kantor of the Crimson Fists Chapter uses a unique relic Storm Bolter known as Dorn's Arrow. The firing rate of this Storm Bolter is astounding: it is able to fire upwards of 300 rounds in just a few seconds. Because of this, Kantor uses a back-mounted ammunition source, feeding the weapon using ammunition belts that feed into either side of the weapon. Dorn's Arrow is mounted on Kantor's wrist, allowing him to freely use both hands while still keeping his weapon ready to fire.
- Codex: Space Marines (5th Edition)
- Dark Heresy: Ascension (RPG), pg. 140
- Dark Heresy: Blood of Martyrs (RPG), pg. 114
- Deathwatch: Core Rulebook (RPG), pg. 147
- Imperial Armour Volume Two - Second Edition: War Machines of the Adeptus Astartes, pg. 32
- Imperial Armour Volume Four - The Anphelion Project, pg. 124
- Imperial Armour Volume Five - The Siege of Vraks - Part One, pg. 148
- Imperial Armour Volume Nine - The Badab War - Part One, pp. 58, 91, 117, 125
- Imperial Armour Volume Ten - The Badab War - Part Two, pp. 65, 75, 100, 115
- Imperial Armour Volume Eleven - The Doom of Mymeara, pg. 112
- Rogue Trader: Core Rulebook (RPG), pg. 122
- The Horus Heresy: Book Seven - Inferno (Forge World Series) by Alan Bligh, pg. 245
- Warhammer 40,000: Rulebook (3rd Edition), pg. 60
- Warhammer 40,000: Wargear (4th Edition)
- Warhammer 40,000: Wargear (2nd Edition)