ST. LOUIS — Visit any St. Louis area gun or gun supply store and you'll find long lines and empty shelves.

"At any given time, probably five to seven people lined up at the register," said Alex Milberg, manager at a tactical supply store in St. Peters.

"Lines out the door. Just a buying frenzy," said Al Rothweiler, owner of Mid America Arms in south county.

Milberg and Rothweiler said they're in short supply of nearly everything. Almost half of Milberg's pre-ordered ammo is already sold out. The stores also are placing strict limits on how many boxes of ammo customers can walk away with.

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While COVID-19 has most businesses shuttered, the gun and gun supply store business is booming.

"We're about four times where we'd normally be this year. A lot of them are looking at economical handguns, handgun ammo," said Rothweiler.

"Three main things have been crazy right now are magazines, ammunition [and a] plate carrier with what's considered level four armor," said Milberg.

Customers like Stacey Hovis lined up with almost a dozen other customers outside Mid America Arms Thursday morning. He said he's willing to forego social distancing for a sense of security in what he fears are uncertain times.

"I feel a lot more at ease knowing I've got that kind of weapon in the event of some unforeseen situation," said Hovis.

St. Louisans may have a unique perspective when it comes to preparing for uncertain times.

"Especially previous issues with civil unrest in the area, and that's always been mentioned, people run out of food, they're hungry, they panic," said Milberg.

Depending on where you live, gun shops are considered essential businesses and will remain open especially if they carry medical supplies.

Pennsylvania Governor Tom Wolf was recently forced to allow gun stores to re-open under their statewide order after the state's supreme court found the governor's actions were in conflict with the Second Amendment.

"That's what I think we're seeing today. People exercising their right to keep and bare arms," said Hovis.

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Even prior to many of the 'stay at home orders', background checks for gun sales were up this year.

In Illinois, gun checks are up 224% over last year, from 190,886 in February 2019 to 620,067 checks in February 2020.

In Missouri, they're up roughly 14% from 42,502 in February 2019 to 48,705 in February 2020.

March figures have not been released.

All of this traffic is causing one issue. If you're trying to get a gun immediately, you may have a bit of a delay. Rothweiler said in 90% of cases, it takes only 20 minutes or so for the FBI's National Instant Criminal Background Check System to provide a result for someone wishing to purchase a gun. Rothweiler explained the system is now so overloaded, he's seen it take up to three days to get those results back. In a statement, the FBI told the I-Team its system is working.

"The FBI is taking appropriate measures to ensure the safety of their employees while remaining committed to ensuring national security and pursuing violations of federal law. At this time, the FBI’s National Instant Criminal Background Check System (NICS) Section remains fully operational and will continue to process requests. The NICS Section appreciates the public's patience during this period of national emergency."

Gun stores also are attracting new customers who've never previously owned a firearm. Milberg said he's glad to to see many firearm training and safety classes in the St. Charles County area booked up for several weeks.

"There's a lot of people coming in telling us how they're new firearm owners, and this is great to hear. But along with that, there are a lot of people desiring to get training," said Milberg. "That's more important than anything because a firearm does no good at all if the person with it has no training, isn't safe with it, doesn't know the laws and legalities of owning one."