A Bombardment Cannon is a type of ballistic starship weapon found almost exclusively is use on the warships of the Adeptus Astartes, including Battle Barges and Strike Cruisers. A Bombardment Cannon is comprised of a turret-mounted electromagnetic linear accelerator that fires Magma Bomb plasma-based warheads at a higher velocity than standard Torpedoes. The Bombardment Cannon, as the name implies, is primarily intended for use in orbital bombardments of planetary surfaces in support of initial Astartes drop assaults. In this way, an Astartes vessel can bombard the targeted region of the planet with Magma Bombs to soften the enemy resistance for the Drop Pods or Thunderhawk gunships containing Space Marines that will immediately follow.
A Bombardment Cannon can also be used as a ship-to-ship weapon in void battles to great effect, where the great destructive force of the Magma Bomb warheads can render even the strongest armour plating irrelevant and destroy an enemy voidship in short order with only a few salvoes.
- Battlefleet Gothic: To Cleanse the Stars - Vessels of the Imperium, pg. 21