Actually they were, when the rate of fire was glitched out.
Or, I could say that winning 1 v 4 battles with a fireshotgun vs guys running armoured is due to my skill but I highly doubt that LMAO.
Now they are not OP but just annoying because they kill you even if you have actually killed the enemy.
Not so much overpowering. Though gets old when in Pont du Hoc, or name the map of choice, it's just deuling fire shells. You can either join them( i keep a blunderbuss loadout with fire shot) or there are a number of ways to avoid/counter. Find new lanes, speed up or slow down...maybe s-mines.