Ionic cannon bugged?

Hi there folks.
I wanted to try out the ionic shotgun cannon on my tank, so i built one. 5 slots which was nice enough. First off i was a bit disappointed that it only has a clip for 8 rounds so essentially has to reload after each shot. But the damage of those shots was even more disappointing. I have then compared it to my trusty old TL 84 plasma cannon and had to realize that the 3-slot Tl 84 gun dealt considerably more damage than the 5 slot TL 100 gun. This seems more than just a little strange to me. I would have expected the shotgun cannon to deal significantly more damage given the difference in TL.
in the time required for firing one salvo from the shotgun and reloading it I can fire two or three salvos from my plasma cannon.
in numbers we are talking 4x 110 versus 8x 80. You don't need to be a math genius to figure out that the latter is more efficient - although it is much lower in techlevel. Now i am wondering why the heck is this so? As i understand it the shotgun cannon is intended to be some sort of burst weapon, but does it really have to have less dps than a plasma cannon sixteen techlevels lower? Seriously?