Ahh bro ok... So for a start the only mag size you could have with a perk that lets you switch would either be 12, 24, 36, 48 etc etc which are all slightly unbalanced options in my opinion but that's beside the point Had to delete some again, too many numbers but basically with the 4 round burst if you miss a bullet theoretically you're only losing 25% of you're damage (whereas it would be 1/3 with the 3 round) or landing every bullet would give you 33% more damage than with a 3 round. It's pretty straight forward logic that per trigger pull you would be dealing substantially more damage, enough to make the inferior choice exactly that... Inferior Although after all that I can think of one use for it and that would only be if you were running low level missions or strikes and you want more bursts per mag to run around getting maybe 1 extra red bar enemy kill per mag size? I'd still take the 4 round burst xD