Avenger Gatling Cannon

The Avenger Gatling Cannon is a ballistic six-barreled, large calibre weapon that fires mass reactive shells at a prodigious rate. These high velocity shots mow down enemy infantry or rip easily through light armour. Well-placed shots can tear through even thicker plating, blasting apart the heaviest armoured infantry or battle tanks. When firing at maximum rate, the Avenger stitches deadly patterns of death across the enemy's front lines while making a whirring hiss as the barrels spin faster than the eye can follow. This deadly weapon is utilised exclusively by various patterns of Imperial Knight armoured walkers.

Sources

Codex: Imperial Knights (7th Edition), pg. 115
White Dwarf Weekly Issue #66 (02, May 2015), "Imperial Knight Warden," "Imperial Knight Crusader," & "Paladins & Errants," pp. 4-5, 10-12, 18, 64-65