These weapons were multi-barrelled Stubbers, using electric motors to maintain an extremely high rate of fire from their spinning barrel. Their medium calibre-slugs lacked the power of bolter shells, but nonetheless the sheer volume of them proved effective against unarmoured hordes of foes and fleshy xenos. Eventually, the more famous Space Marine Assault Cannon was developed from the Rotor Cannon.
Their origins obscured by time, many patterns of weapon employed by the Space Marine Legions date back to the Dark Age of Technology or before. Simpler to produce than most heavy weaponry, the Rotor Cannon found use in many Legion Tactical Support squads.
Rotor Cannons are commonly carried by a Voidsman-At-Arms to augment the firepower of their squad. These weapons have earned a variety of nicknames such as: whirgun, deck-clearer, and the Emperor's chainsaw.
Unknown origin, in use since long before the coming of the Emperor and the Age of the Imperium.
Heavy Rotor Cannon
The heavy rotor cannon is an improved version of the humble rotor cannon that fires larger calibre ammunition and possesses more robust motors for the barrel assembly. While still not matching the power of the assault cannon that would render it obsolete, it was superior to the standard rotor cannon and its lighter weight allowed it to be attached to the small Estoc Pattern Jetbikes without compromising their agility.
Used by the Salamanders during the Horus Heresy. These weapons have much in common with the multi-barrelled, rotary weapons commonly found in Legion arsenals but are enhanced with the use of specialist rounds, tipped with a hyper-hardened mineral naturally formed from the pyroclastic flows of Nocturne's oldest volcanoes.
Unlike the more common rotor cannon carried by Space Marine support troops, the snub rotor cannon sacrifices range for a vastly increased ammunition capacity and greater rate of fire. It generates such a hail of projectiles that even heavy armour is not fully proof against the weight of firepower these weapons can produce.
- 1: The Horus Heresy Book One - Betrayal, pg. 233
- 2: World Webstore - Rotor Cannon Set (accessed 2/22/2020)
- 3: Codex: Elucidian Starstriders (8th Edition), pg. 10
- 4: The Horus Heresy Book Two - Massacre, pg. 104
- 5: Exemplary Battles of the Age of Darkness: Volume One, pg. 93, Chapter "Purging of the Invocastus Sector"
- 6: The Horus Heresy Book Nine - Crusade, pgs. 194-195