And what constitutional understanding forms your opinion concerning semi vs. full auto?
"And what constitutional understanding forms your opinion concerning semi vs. full auto?"
More pragmatism than anything else - throw the anti-gunners a small bone. A M16 is only really useful in the semi-auto mode. The M16A1 used to have a full auto mode, and it wasted ammo with few hits. So, when they came out with the M16A2 they converted the full auto mode to 3 round bursts. A skilled rifleman can do just fine with semi-auto only.
However, there is no reason to force civilians to remove flash suppressors or bayonet lugs. That is just plain silly. Plus, it renders the weapon useless for "militia" duty.