1) Determine if mine enemies suffer from allergies
2) If so, design a weapon that sprays a concentrated stream of a given allergen at them
3) If not/in addition, use it as a non-lethal crowd-control device in place of pepper spray, light-dazzle, and sound emitters
4) Of course, also create a lethal version that just sprays the allergens really, really fast
5) Remember: everyone is allergic to depleted uranium moving at a high velocity