Direct the Justice Department to look at imports into the United States of guns limited to being primarily for SPORT.

One thing the president could do immediately without legislation, that he has the executive power to do, Direct the Justice Department to look at imports into the United States of specific kinds of guns. Federal law already exists regulating the import of firearms says that any firearm brought into the United States must have been primarily designed for sporting purposes.
Presidents George H. W.Bush and President William Clinton, used this power. They directed the ATF to look at these guns and the ATF said that these kinds of guns are not really primarily for sport. So they did ban the import of certain classes of assault rifles.
President Obama could do the same thing with the stroke of a pen. Let's weed out guns that aren't for sport! Including assault pistols.