From Guns.com:

With reported widespread glitches and bugs in California’s new bullet control plan, Second Amendment groups are promising to soon see the state in court. Gov. Gavin Newsom’s Proposition 63, which among other tenets requires a background check on every ammunition sale in California, kicked fully into effect this week and in many cases left a bad taste in the mouths of would-be ammo buyers.
The Associated Press reported long lines at gun stores and confusion about the new regulations along with delays and frustration. One gun owner documented his experience being denied the opportunity to attempt a check even though he had a current California driver’s license and U.S. passport. Such problems, say gun advocates, cues up the new law for a legal challenge.