Firing a gun deteriorates the gun. Understood. Now compare firing a single shot sniper rifle to firing a burst gun. Bursting would deteriorate a gun faster. That sniper rifle should last way longer.
Idea is to make single-shots do far less deterioration to a weapon. So keep it the same when bursting but reduce det for single-shots.
Comparing Sniper riffle to an AK are 2 different things, with different design, one designed for burst the other for precision.
However burst vs single shot on the same weapon, should definitely have different deterioration penalty. (If burst is 6 bullets, then it should deteriorate a weapon 6 times more than a single shot)