The Crucible Industries Maelstrom-12 is a fully automatic shotgun chambered in 12 gauge, fed from a twenty-round drum magazine, with a cyclic rate of 300 rounds per minute. The weapon features a constant-recoil operating system that spreads the recoil impulse across the entire firing cycle, making automatic fire from a 12-gauge shotgun controllable — though 'controllable' is a relative term when discussing a weapon that fires five buckshot shells per second.

The Grinder is a siege weapon in a shotgun's clothing. At room-clearing distances, a sustained burst from the Maelstrom saturates an area with buckshot pellets in a density that no individual target can survive and no group of targets can avoid. The twenty-round drum empties in four seconds of continuous fire, during which time the weapon has dispersed approximately one hundred and eighty individual buckshot pellets into the target area.

Crucible manufactures the Maelstrom-12 under exclusive contract for corponation military forces and high-tier facility defense. The weapon is not available on the civilian market at any price through legitimate channels. On the black market, Grinders command prices that rival small vehicles, and their appearance at any criminal scene triggers an immediate corponation response — the weapons are serialized, tracked, and actively hunted when they leave authorized custody.