A Vulcan Mega Bolter is an immense, hydraulically-driven, five-barrelled, air-cooled, electrically-fired rotary Bolt Weapon. The Vulcan Mega Bolter is one of the most potent and effective anti-infantry weapons available to the Imperium, and easily carves through swathes of heretics or xenos with mass-reactive shells larger than human skulls firing two at a time, leaving a heavy carbonised reek in the air. So large and powerful is the weapon that it must be mounted onto the massive arms of an Imperial Titan, or mounted on the hull or turret of a Stormlord super-heavy tank -- little else could handle the ground-shaking recoil or bear the weight. This weapon is comprised of massive dual heavy-calibre, rotating Bolters with multiple barrels. Its staggering rate of fire makes it an ideal weapon for use against infantry, light vehicles and even small structures.
The use of Vulcan Mega Bolters on Titans dates back to before the tragic ending of the Great Crusade, and, as such, many Chaos Titan Legions also possess them within their own heretical arsenals. On their quest for destruction, they use them liberally, and to brutal effect. On the Shrine World of Gundora in the Tratoll System, corrupted Titans in possession of this weapon tore the entire 44th Cadian regiment to shreds. So relentless was the bulletstorm that some Cadian vehicles were later discovered half-buried, the pressure of the many impacts having pushed them under the sands.
It was the Forge World of Lucius where Tech-Priests first experimented with mounting the Vulcan Mega Bolter, usually reserved for Titans, onto tank variants. Having long been adept at the arcane construction of god-machines, they began attempting to transfer the weapon across to other vehicles in late in M33. Many of the machine spirits reacted badly to these efforts and failed rituals led to the destruction of many tanks before relatively stable patterns were developed. As Servitors mount this weapon onto Stormlords or even Macharius "Vulcan" variants, Enginseers pour sacred unguents over the cogs to placate the volatile machine spirit into accepting the modifications. When all the components and rituals come together, and the violent machine successfully comes to life, it takes a particularly brave or wild crew to risk driving the unified vehicle into battle.
The renegades of the Dark Mechanicus do not possess the ritual knowledge for successful transference of the Vulcan Mega Bolter onto tanks. Therefore it is only the Chaos Titans that march to war armed with the Vulcan Mega Bolter. However, reports of defiled variants of Stormlords have been reported on Orax near the battlefront of the 13th Black Crusade. The Vulcan Mega Bolter was seen being put to treacherous use against the civilian populations and have helped disable two-thirds of the planet's manufactorums.
The Vulcan Mega Bolter is essentially two rotary cannons mounted together, each with multiple barrels the size of an Autocannon. The regularly blessed cogs then rotate at phenomenal speed; in the blink of an eye, two loaded barrels click into place, and another pair of shells are unleashed. It is this rapid rate of fire, combined with the explosive power of the mass-reactive shells, that makes the Vulcan Mega Bolter able to rip thick gouts out of whatever the enemy throws at them. With sophisticated navigation and target identification tools, the Vulcan Mega Bolter can be used effectively even against concealed targets.
While a Titan is in combat, one crew member tends to a mag-crane in the arm that feeds the thick chains of shells in a constant flow to the weapon itself. Loaded onto the Titans using massive grav-hoppers, these chains contain enough shells to last through days of the most violent battles. Meanwhile, a second crew member continually evokes the Litany of Reloading and Redemption, as sanctioned by the Adeptus Mechanicus, to ensure the smooth release of ammunition and that the plentiful supply of mass-reactive shells continues to load. He pours blessed oils into the whirring mechanisms whenever the Vulcan Mega Bolter is in danger of overheating. Within super-heavy tanks, similar large bolt chains are fed into the weapon by two crew members, both of whom are tireless in their muttering of prayers and offerings of blessings. Knowledge of these specific arcane practices is restricted by the Tech-Priests of Mars, which is one of the reasons the Vulcan Mega Bolter is not more widely observed on the battlefield.
Whether mounted on a Titan or a Stormlord, the Vulcan Mega Bolter is used to pulp waves of troops with its withering fire, as shells shred their formations without mercy, clearing the way for the Imperium’s defenders. Even small vehicles such as lightly armoured tanks are blown into jagged pieces, their metal hulls buckling under the incessant fire. The fire of Vulcan Mega Bolters has been unleashed across war-torn worlds for thousands of years by lethal Titans stalking their foes. They have shredded buildings that harboured xenos adversaries and excoriated Daemon-infested hives from the surface of innumerable planets. They have carved paths through tides of greenskins stretching from horizon to horizon, and have been found to be of particular use in dealing with large swarms of Tyranids, cutting up waves of advancing Gaunts, felling hulking brutes and filling the air with shredded chitinous fragments and alien blood.
So large and powerful is a Vulcan Mega Bolter that it can only be mounted on the hull of Stormlord super-heavy tanks or on the massive arms of a Titan -- little else could handle its ground-shaking recoil and immense weight. The Vulcan Mega Bolter is commonly fielded to provide cover for other Warhound-class Titans and Imperial super-heavy tanks and to ensure the suppression of enemy heavy weapon positions with a devastating storm of shot and shell. The Vulcan Mega Bolter also provides a Warhound-class Titan with unparalleled anti-infantry firepower. This weapon can also be mounted on Reaver-class Titans and even the mighty Imperator-class Titan, which carries an even larger version of this devastating weapon.
- Imperial Armour Volume Three - The Taros Campaign, pp. 251-254
- Warhammer 40,000: Apocalypse, pg. 125
- Warhammer 40,000: Apocalypse (6th Edition) (Digital Edition), pg. 363
- Warhammer 40,000: Munitorum - Vulcan Mega Bolters (Digital Edition)
- Titanicus (Novel) by Dan Abnett