The Assault Cannon is a rotary storm of death, its cluster of spinning barrels disgorging shells at a rate that turns the air itself into a wall of shrapnel. In seconds it can chew a squad to red ruin or strip the armour from a battle-tank, its howling report unmistakable across any war-zone. It is a weapon of overwhelming, indiscriminate slaughter.
Only the strongest can bear it. Among the Space Marines it is carried by Terminators whose armour absorbs its titanic recoil, or mounted upon Dreadnoughts, gunships, and Land Raiders that provide the ammunition feeds such a beast demands. The weapon's appetite is voracious, and its bearers march into battle trailing belts and drums of ammunition to feed its endless hunger.
Yet the assault cannon is a temperamental machine-spirit, prone to jamming and catastrophic barrel failure if its firing rites are neglected. Techmarines lavish it with oils and prayers, coaxing forth its fury while guarding against the moment its own violence turns inward. To hear its scream is to know that the enemy's line is about to cease existing.