Simple fix - just like the door breach exploit where players are punished with traps, if a player exceeds what the realistic upper limit of the weapons fire rate, the weapon should malfunction catastrophically and down the player. It literally has a pressure tank on the top of the weapon, have it blow and shred the player with shrapnel. Real automatic weapons will do this if a round jams and cooks off, particularly with larger calibre rounds, but it stands to reason if the kettle can't function due to overpressure, it should detonate.
There could be different levels to this, it could simple blow and render the weapon broken, it could hurt the player with varying levels of damage... Up to Embark.
