From the post:
Boromites are practically-minded, physically strong human morphs whose ancestors were bio-engineered in ancient times to work as deep-space asteroid miners. They are skilled engineers, often adapting or repurposing equipment that falls into their hands.
One such machine is the mag mortar, a powerful weapon with a massive blast-effect designed for pulverising enemy fortifications from short ranges and for clearing troops from prepared defences.
Mag mortars are magnetic launchers designed to undertake siege work and to support assaults upon fortifications or other fixed positions. They hurl a heavy shell at low velocity and rely upon the explosive power of the shell itself to smash the enemy apart. They are very adaptable and can also shoot special munition types when required. Mag mortars make excellent close support artillery and can be found fighting in the thick of the action.