The Questoris Battle Cannon is a variant of the Battle Cannon commonly found on Imperial armoured vehicles. The Questoris Battle Cannon was once used by the combat walkers of the Questor Imperialis, the Imperial Knights, and by the Renegade Knights of the Questor Traitoris and was deployed predominately on the Knight Paladin and the Knight Crusader armours.
These weapons are akin to a large-calibre, ballistic artillery cannon, and feature an automated loading system that allows them to fire accurate, highly-explosive shots at a rapid rate. The explosions are capable of racking up a horrific number of casualties when employed against massed infantry hordes, yet are also capable of destroying light and medium tanks with ease. The Questoris Battle Cannon was used during the Great Crusade and Horus Heresy eras, although it seems to have been mostly replaced with the Rapid-Fire Battle Cannon by the late 41st Millennium.
The Questoris Battle Cannon differs from the Rapid-Fire Battle Cannon in that it uses smaller, less powerful ammunition, but features a slightly higher rate of fire. Like the Rapid-Fire Battle Cannon, the Questoris Battle Cannon also features a Heavy Stubber mounted to the weapon's gun shield, which is used to engage enemy infantry that get too close.
- The Horus Heresy - Book Four: Conquest (Forge World Series) by Alan Bligh, pg. 301
- The Horus Heresy - Crusade Imperialis Army Lists, pg. 112