Ok, so maybe it's not technically a tank and is, instead, an armored mobile artillery piece. But that's just terminology. Anyway, Forge World is now taking orders for their new Legion Arquitor Bombard with Graviton-Charge Cannon kit. If you want to blow giant holes in the enemy's battle lines, this is a good choice for that. They're also taking orders for the softcover version of Horus Heresy Book 8.
From the post:
The Legion Arquitor Pattern Bombard is a heavy artillery platform designed to operate at the forefront of the Legiones Astartes advance. Equipped with a reinforced chassis and brutal short range firepower, it is called upon to break the most stubborn of fortifications or to annihilate massed enemy infantry and armour.
Available to both Loyalist and Traitor forces, the Legion Arquitor Pattern Bombard can be fielded in units of up to three vehicles. The graviton-charge cannon fires energised canisters that impact among the enemy's ranks, emitting a graviton field that crushes delicate circuitry and electronics, disrupting the advance of anything that survives the barrage. You can also add even more firepower to your indomitable artillery platform in the shape of sponson-mounted heavy bolters or autocannons. If you need to add mobile heavy firepower to your force, the Arquitor Pattern Bombard is ideal.
This highly detailed 56-part resin kit makes one Legion Arquitor Pattern Bombard with Graviton-Charge Cannon.
Rules for fielding the Legion Arquitor Pattern Bombard are available as a free PDF download.