Gravgun

Grav-gun are weapons used by Space Marines that directly affect the local gravity of the target, giving them an interesting effect in game.

It is range 18' S* AP2 Salvo 2/3 with Concussive and Graviton.

With the Graviton rule the gun doesn't roll to wound like normal, instead it wounds based on the targets armor save. For example anything with a 2+ will be easily wounded, while stuff with a 5+ will be harder to wound. When rolling to penetrate against vehicles a 1-5 will do nothing however a 6 will instantly immobilize it.

Grav weapons were introduced to the Marines in their new codex, however they have a rather mixed reputation amongst the player base. While they can easily kill MEQs they are largely useless against light armor.