We're not arguing what's a more effective weapon in the hands of a soldier. Sure, 3 bursts are better than full auto, but that's a selection.....as in OPTION, be it semi-automatic vs 3 burst vs full auto, that a soldier has when handling an assault rifle. That's not at issue.
The issue is WHAT makes a rifle an assault rifle, and that would be that it be able to perform full auto If it can't, it's not an assault rifle. Simple as that. If you try to alter a semi-auto into a full auto, THAT'S ILLEGAL, so best not being bragging so much on how you can do that