We'll have to wait until Tuesday to see the details of Vice President Joe Biden's 2016 presidential campaign platform gun control recommendations, but already we know that it's likely be heavy on pandering to the gun-averse political base, and light on anything that might leave the administration dangling in the breeze when it comes to the hard business of enforcement. (You'll note that I didn't say "effective" because, when it comes to reducing crime or violence, restrictions on firearms ownership offer little hope of being "effective.") Biden is steering well clear of anything on which compliance or the lack thereof could be easily measured, such as a ban on existing semi-automatic rifles, and jauntily touting an ethereal "emerging consensus" on "universal background checks" for gun sales, even between private parties, and a ban on the sale of new high-capacity magazines. Passing such restrictions will likely require a battle in Congress, but whether such proposals win or lose, the administration will stroke those supporters who fret over metal objects that make loud noises — and then walk away from the laws they've passed without worrying overly much about having accomplished nothing.
First, huge numbers of high-capacity magazines are already in circulation. Under the last ban, the price went up, but they were still available, and more have been made and sold since. Even if sales of existing magazines are forbidden, they'll still exist, and change hands quietly. That is, aside from the ones that people are already manufacturing on hobbyist 3D printers or in metal shops. Getting existing magazines out of circulation is a non-starter, since nobody knows where they are and most owners are unlikely to surrender them when keeping the things is essentially a risk-free enterprise.
Which is the same problem faced by the "universal background checks" Biden insists are part of the emerging consensus he perceives among the people who already agree with him. The background check brainstorm is a bone thrown to people who heard somewhere about a "gun show loophole" — not realizing that most private owners can sell free of paperwork requirements anywhere, in the majority of states, while commercial dealers have to do background checks, even at gun shows. Americans own an estimated 270 million firearms (PDF), most of them unregistered. Even records in those few states that require some sort of registration are compromised by the fact that owners move out of state, or in-state from elsewhere, and the lists become inaccurate and unreliable over time. A gun owner in New Jersey, for instance, where multiple levels of paperwork are maintained, could move to bureaucracy-free Arizona, then move back to Trenton (for reasons I could never fathom) and plausibly deny still owning any of the guns the state of New Jersey meticulously recorded.
Since the vast majority of firearms exist in private hands with the same status as chainsaws or propane torches — that is, untraceable after the point of sale — a "universal background check" law would be nothing more than a pretty-please request by politicians to expend time, effort and (probably) money running a purchase through a bureaucracy when it could more easily be settled cash-and-carry over a kitchen table. Sure, some people will comply, but that will be a voluntary matter.
But the impotence of a magazine ban and the vast non-compliance a background check law will face will be relatively quiet matters, while the passage of such laws will be like so many Ol' Roy treats tossed to the do-something-now crowd who won't know the difference.