I do not think you understand how EO works?
POTUS can only EO based on laws Congress has passed that give him specific authority, like to decide whether a gun is sporting use or not.
I agree with Renegade's comments. That's why I posted a couple of historical Executive Orders.
It's possible that he could try and restrict certain types of ammunition based off of its' interpretation of sporting use:
BATFE Taking Comments on "Sporting Purposes" Exemption to "Armor Piercing Ammunition" Law Until Dec. 31
http://www.nraila.org/news-issues/a...mor-piercing-ammunition-law-until-dec-31.aspx
Or He could try and restrict/redefine whether a certain firearm is of sporting use or not. Recent examples to this would be:
8/10/1999 - Bureau of Alcohol, Tobacco and Firearms
IMPORTANT NOTICE
ATF Rulings 94-1 and 94-2 classified three shotguns as destructive devices pursuant to 26 U.S.C., Chapter 53, the National Firearms Act (NFA). These shotguns are the USAS-12, Striker-12, and the Streetsweeper. The NFA requires registration of certain types of firearms such as machineguns, sawed-off rifles, sawed-off shotguns and destructive devices. The NFA defines destructive devices to include shotguns with a bore of more than one-half inch diameter which are not generally recognized as particularly suitable for or readily adaptable to sporting purposes. The Bureau of Alcohol, Tobacco & Firearms (ATF) has determined that these shotguns fall within this definition.
Classifying these weapons as destructive devices under the NFA requires the current possessor to file an ATF Form 1, fingerprint cards, and a current photograph to effect the registration of the firearm. The initial registration is tax exempt. Any subsequent transfer must be approved in advance and would result in transfer tax liability of $200. The possessor must register the weapon as soon as possible after learning of the registration requirement, e.g., within thirty days. Weapons not registered within the allowable time frame are subject to seizure and forfeiture, and the possessor subject to a criminal fine of up to $250,000 or up to 10 years in jail, or both.
STREETSWEEPER - IMPORTANT NOTICE