"So much is just out of stock," said Gavilan Hills resident Steve Sembera, who's been monitoring online sales throughout the state.
"You're kind of limited on now what you can buy. Whatever they have left you're buying."
Some gun store owners believe people are stocking up on ammunition now, because they're unsure of how the background check process will work on July 1, when it's scheduled to be implemented.
The new requirements are part of Proposition 63, which was approved by 63% of voters in 2016. Part of the law requires certain individuals to pass background checks to purchase ammunition. But details of how the new requirements will work have yet to emerge.
"I can tell you right now a lot of my customers are confused," said Norris Sweidan, owner of Warrior One Guns and Ammo in Riverside. "It's going to be a total mess."
Sweidan received a notice from the State Department of Justice nearly two weeks ago, detailing the equipment he needs to have ready to comply with the new requirements: an internet connection; a computer; a magnetic card reader. But he said the notice doesn't say how the process will work when the system becomes active on July 1.
"I don't know how it's going to work. I don't know if you're going to wait one minute or 10 days for your ammo."
Sweidan questions whether these additional background checks are necessary, saying there are already waiting periods and background checks on those who purchase guns, and a thorough process for checking up on those who obtain concealed weapons licenses.
"You've already been vetted through the system," said Sweidan. "You just don't need it."
He wonders whether criminals who are denied the ability to purchase ammunition will simply obtain it from another state.
"What is going to... prevent you from going across state lines and picking it up somewhere else," asked Sweidan.
"Having a background (check) on ammunition is not going to stop a criminal."