The most common configuration for the sponson-mount is 2 Heavy Bolters or 2 Heavy Flamers. The Conqueror, like all Leman Russ variants, can be equipped with two sponson mounts, one on each side. The Conqueror is also one of only two Leman Russ tank variants that have a co-axial weapon mounted on the tank's turret, the other being the Leman Russ Vanquisher. The Leman Russ Conqueror's main weapon, the Conqueror Cannon, is a smaller and less powerful version of the Battle Cannon used on the baseline Leman Russ, but the reduced size and firepower allow the tank to move while firing and maintain a higher rate of fire. The turret also has additional armour plating on the forward side, improved air-intake valves and vents, and a rear hatch that can be used to quickly re-arm the tank and also to dispose of spent shell casings without a crew member having to leave its armoured interior. The Conqueror is one of only two Leman Russ variants that makes use of a co-axial weapon, the other being the Leman Russ Vanquisher.
The space saved in the turret also allowed for the use of a co-axial Storm Bolter. The weapon's use of smaller shells allowed the Conqueror to carry more ammunition and thus made it less reliant on re-supply during operations. The weapon's smaller size also gave the vehicle greater mobility, and allowed its loaders to keep up a high rate of fire. The weapon was shown to have greatly reduced recoil due to the gun's torsion bar counter-balance mechanisms, and this provided the new tank design greater accuracy when firing on the move. When the designs were originally found many within the ranks of the Adeptus Mechanicus feared that the Conqueror Cannon's smaller size would result in a loss of firepower and poor battlefield performance when compared to the standard Leman Russ' Battle Cannon, but these fears were laid to rest during the weapon's field testing.
The Standard Template Construct designs for the Leman Russ Conqueror were rediscovered on the Forge World of Gryphonne IV sometime during the 38th Millennium. Although the Leman Russ Conqueror is relatively new to the Imperium's arsenal, it has already proven itself as a capable line-breaker tank, used to penetrate and surround the formations of enemy armour. The Leman Russ tank has many variants, and the Conqueror is one of the most uncommon, as the Standard Template Construct (STC) designs used in its construction were only recently rediscovered by the Adeptus Mechanicus. The Leman Russ Conqueror variant differs from the standard pattern Leman Russ in that its main weapon is a Conqueror Cannon, as opposed to the Battle Cannon. The Leman Russ is named after the Primarch of the Space Wolves Space Marines Chapter, Leman Russ, and is one of the most common armoured vehicles used by the Imperium of Man. The Leman Russ Conqueror is a variant of the Imperial Guard's primary main battle tank, the Leman Russ.