An unanswered question in the Florida gun debate: What to do with existing guns?

It is impossible to know how many guns are in Florida, but allow us to provide an estimate: a lot.

Background check data provided by the Florida Department of Law enforcement indicates that the state has conducted background checks on more than 6 million gun purchases through its Firearm Purchase Program since 2011. However, that data does not account for all gun sales — let alone gun gifts or donations. PolitiFact notes that counting guns is notoriously difficult for researchers.

Still, the little data we have tells us that the Sunshine State is awash in guns.

So here's the question: How would a ban on new weapons stop mass shootings in a state already filled with guns?

If that sounds like a National Rifle Association talking point, it's because it has been.

Liberals say the NRA's logic is self-serving.

"One of the problems the NRA exploits is just how prevalent these arms have become because our laws are lax or non-existent," Sen. Jose Javier Rodriguez, D-Miami said. "Well that's something that frankly the NRA and the NRA's allies have created."

But some experts say even the most restrictive policies proposed by Florida legislators this session — assault weapon bans, magazine size restrictions, firearm registries, etc. — would do little to cut off people's access to dangerous weapons.

When the Senate debated SB 7026— the gun legislation that just landed on Gov. Rick Scott's desk — Sen. Linda Stewart, D-Orlando sponsored an amendments that would have banned the "sale or transfer" of certain assault weapons. Under the proposal, Floridians would have had until July 1, 2019, to obtain a certificate of possession or remove their assault weapon from the state.

A policy like that would pose logistical challenges, experts said.

"If all gun sales were banned tomorrow, there'd still be plenty of guns in the U.S. in 25 years," Jay Corzine, a professor of sociology at University of Central Florida said. Corzine researches the impact of different weapon types on mass shootings. He added that such a ban would likely be subject to legal challenges.

"Once guns are out in circulation, it's very difficult to bring them back," said Jaclyn Schildkraut, an expert on mass shooting research and an assistant professor of public justice at the State University of New York at Oswego. She noted that many gun control measures would punish law-abiding gun owners while likely doing little to deter criminals — who commit all mass shootings — from obtaining weapons.

Read more: The Tampa Bay Times spent 10 months investigating Florida's stolen gun problem. Here's what we found. 

And any retroactive ban on weapons already purchased, the experts said, would play into the NRA's narrative of a government out to get your guns.

Those factors put Florida Democrats in a tough spot. But Rodriguez said the scale of the challenge shouldn't be an argument against addressing it.

"There are all kinds of ways of dealing with the fact that, yes, these weapons are very prevalent right now," Rodriguez said, citing programs like gun buybacks. "It's a question of the state dedicating resources to a problem."

But, as Schildkraut noted, an individual policy's effect on mass shootings is less clear.

"We've seen already that the presence of a federal assault weapons ban doesn't stop a mass shooting," Schildkraut said, citing the 1999 Columbine High School shooting in Colorado. At the time, certain assault weapons were banned by federal law, but the shooters used weapons that didn't meet the federal definition. (Corzine added that even if the Legislature were to pass an assault weapons ban, gun manufacturers would likely find away around it by manufacturing guns that failed to meet the ban's technical definitions.)

Schildkraut said although she doesn't believe civilians need assault weapons, lawmakers should focus primarily on strengthening existing gun laws. She noted the law enforcement failures in the run-up to the Parkland shooting and the Sutherland Springs, Texas, massacre that claimed 26 lives.

"Because the laws aren't being enforced the way that they're supposed to, and people aren't being held accountable, it's giving (potential shooters) less friction in trying to carry out their plans," Schildkraut said.

There is a bipartisan proposal in Congress to strengthen the National Instant Criminal Background Check System — but momentum to pass even modest gun legislation in Washington, D.C., could be slowing. Proposals that mandate universal background checks for all gun purchases have the overwhelming support of voters — but are unlikely to pass in Washington or Tallahassee anytime soon.

Even if new laws aren't the answer, Schildkraut said, "Our job in society is to make (mass shootings) more difficult, not to make (them) easier."