CA Lt. Gov. proposes POS background checks to buy ammo. Will this curb gun-related violence or create a new black market?

Aside from the ammo background checks, the California proposal also would require felons to relinquish weapons, and ensure that data is shared with the federal firearms database on residents who are prohibited from owning guns.
Gun control advocates welcomed California's proposal, pointing to the lack of political will at the federal level. Newsom made his announcement in San Francisco near the site of a 1993 gun massacre that helped spur federal restrictions on assault weapons."Congress has failed to pass even the most basic laws to help keep guns out of dangerous hands and save lives," said Kate Folmar, spokeswoman for Everytown for Gun Safety, a group founded by former New York Mayor Michael Bloomberg. "The states have and will continue to take action to reduce gun violence despite the gridlock in Washington." Polls have shown California voters are generally more supportive of restricting access to guns than voters in other states.
http://www.foxnews.com/politics/2015/10/19/top-california-official-pushes-ammo-background-checks/?intcmp=hpbt1