AT70 Reaver Battle Tank
The AT70 Reaver Battle Tank was a main battle tank produced by the Forge World Urdesh and it was considered as the cheap knockoff of the venerated Leman Russ Battle Tank. As such it is seen as the Leman Russ' version of the Baneblade's Macharius Heavy Tank.
The AT70 was considered an inferior design compared to the standard tank of the Imperium, the Leman Russ Battle Tank. The tank lacked any Auspex or laser rangefinding equipment, requiring the gunner to aim by visual methods only. It also lacked any gyro stabilizers, limiting its ability to hit targets while moving. The AT70 was armed with a hull-mounted lascannon and a 105mm hypervelocity main gun, which had a slow rate of fire and was unable to penetrate the side armour of a Leman Russ. Yeah...not looking too hot eh? In game terms that'd probably mean that the gun would have a strength value of 7 or 6 back in the days before GW shifted to an "anything can wound anything" approach in 8th edition. Which would definitely be absolute shit for a single shot tank gun. We're talking "like a nova cannon without the ability to ignore cover" or "one S7 AP4 small blast shot" levels of shit.
Due to their inferior quality, Reavers were only a threat to Imperial armoured forces when they outnumbered them. The only reason why they are still made, is due to their low cost and ease of manufacturing in places where the technological advancements or resources are dirt poor that this is seen as the only alternative to a tank. But one must ask themselves how shit of a Forgeworld Urdesh is, if this is the only main battle tank they can make despite the blueprints of the Leman Russ being found everywhere.
AT70s can also be equipped with twin-linked autocannons in place of the main battle cannon. This was originally for use in heavy suppression operations during hive riots; it has since become the bane of many Imperial Guard units pinned down by enemy fire. Before you point to this as proof of its superiority over the Predator Destructor, note that 8th edition makes it very clear that the Predator Destructor's cannon is not your regular garden variety autocannon with its 2d3 shots and thus having on average at least twice and possibly as much as thrice the in-game dakka of a normal autocannon. Out of game, random numbers of shots usually mean that the gun in question is some sort of explosive, which means the Predator cannon can launch explosive shells powerful enough to threaten multiple bunched up targets at once which regular autocannons don't get.
When the forces of Chaos captured Urdesh during the middle of the Sabbat Worlds Crusade, many Urdeshi-designed weapons and vehicles were produced in great numbers to equip their forces, including Reavers (No, not the one you’re thinking, although it would be awesome if it was really these murdermachines). Among those who used the tanks was the Blood Pact which just so happens to be the biggest user, which was often engaged in heavy fighting with Imperial forces, especially against the Tanith First and Only led by Colonel-Commissar Ibram Gaunt. With the recapture of Urdesh by Imperial forces, use of the AT70 by the Blood Pact would eventually decline, though given how the thing is basically made out of old duct tape and spit it's possible that any half sane blood pact member could put together an equivalent machine in their basement.
Many people have attempted to make AT70s (and AT83s). Many do this using minor variations on two main themes (the same two themes used for converting most fluff-only vehicles in 40k).
The first is to use a Chimera chassis and then either give it a Leman Russ turret or to use an entire LR chassis with Chimera tracks (this author’s preference is to the latter method, preferably using the old, derpy LR turret).
The second is to take a historical tank (often at 1/35, but vehicle scaling is fucky in 40k, so YMMV), and dress it up in Chaos iconography. Tanks from Warlord Games' Bolt Action are a good choice for that, as their scale more or less matches that of 40k. Whichever way you do it, you will need red paint. A lot of red paint.
AT70 conversions, when you thought the Malcador Heavy Tank was dated. (These seemed to have been converted from some Panzer IV's).