I have posted an answer on this topic more than, once, but it's not in the President's power to enact on his own --
A year of compulsory national service, thus taking the "well-regulated militia" phrase of the 2A seriously. The year could be accomplished within 5 years of HS graduation (or by age 25 if not a HS graduate), consisting of basic military training, specialty weapons/tactics training for those capable and willing, and service in a hard-to-fill billet for the remainder of the time, perhaps just KP duty in support of the basic/specialty training. Successful completion of the weapons training would permit the citizen to possess a standard weapon issued to him to be maintained in his residence for use in times of national need. The "year" could alternately be completed by a 4-year program similar to ROTC with a reserve officer's commission at college graduation. For those opposed to military training, an alternate one year (or four 3-month segments) of service, similar to local community service programs but on a national scale -- things like National Forest/National Park grunt work, service as an orderly in a VA hospital, or something similar.
This would not only have the benefit of added manpower at low cost, but also the benefit of weeding out those who should never have access to powerful weapons.
^^^^That's your solution to gun control and crime in America?!?! I bet you sat there and thought your were forming a well-thought answer. I'm sure all the criminals will just be beating the recruiter's office door down to get in and sign up. If that's all you could come up to solve gun control problems, which in reality is a crime-related problem, since law-abiding citizens don't break the law, then we really are destined for failure.
Access to powerful weapons? How do you define who has access and who doesn't? You could say a 9mm is a powerful weapon. Yet my 10yo has been shooting since age 7 and has better safe gun handling skills than many adults I've seen around firearms. And don't get me started with criminals. It's obvious how they view firearms. Especially the ones who aren't permitted to have one, yet still seem to find access to one and commit more crimes.