Without bullets, slugs or shot, a gun is no deadlier than a steel club. But the question of how to keep firearms' lethal projectiles out of the wrong hands has historically been a low priority for regulators more concerned about the guns themselves.

That could be changing. As the nation debates competing proposals to reduce gun violence, some law enforcement leaders and elected officials argue it's time to examine an area they say is especially devoid of common sense regulation: the buying and selling of ammunition.

They say there is an obvious inconsistency in federal and state law. While it is illegal for certain classes of potentially dangerous people — such as felons and the mentally ill — to possess bullets, nobody's checking. Ammunition buyers don't have to undergo the background checks required of gun purchasers.

"My view of it is that it becomes, in essence, a meaningless law," Pinellas County Sheriff Bob Gualtieri said, referring to the largely unenforced provisions of federal and Florida law that bar convicted criminals from possessing ammunition. "It's a law without any teeth."

A background check for ammunition as well as guns, Gualtieri said, "makes all the sense in the world to me."

Gualtieri is an elected Republican, but his rationale is similar to that of a prominent politician from the other side of the political spectrum. U.S. Sen. Richard Blumenthal, a Connecticut Democrat, has introduced a bill that would establish universal background checks for ammunition purchases. The law would also increase record-keeping obligations for ammo sales and require retailers to notify the police when one person buys more than 1,000 rounds.

Speaking to the Tampa Bay Times by phone Thursday from Washington, Blumenthal said his proposed legislation was rooted in the concerns expressed to him by police in his home state.

"My bill originated from my conversations with law enforcement officials," Blumenthal said. "They told me, 'Here's a glaring gap in the law.' " Such checks, he added, are "common sense, and common ground for anyone who wants to enforce the existing laws."

Hillsborough County sheriff's Col. Donna Lusczynski said any proposal to expand background checks to include ammunition should be scrutinized to determine that it "doesn't, in fairness, overburden some of the businesses" that sell most of their merchandise to law-abiding customers.

But in light of the existing system's shortcomings, she said, ammo background checks are "something we need to look into."

The massacre of 20 children and six adults at Sandy Hook Elementary School in Newtown, Conn., might not have been affected by tighter ammo regulation. The 20-year-old gunman at Sandy Hook, Adam Lanza, had no criminal record. But in Pinellas County, another chilling case demonstrates the existing laws' shortcomings.

Benjamin Bishop, an Oldsmar 18-year-old, has been charged with two counts of first-degree murder. Authorities say he killed his mother and her boyfriend in October with a shotgun. Bishop had a criminal record, so he had to have a friend buy the gun for him, detectives say.

The ammunition was a different story. In a jailhouse interview with the Times, Bishop said he twice went to an Oldsmar gun store to buy rounds of ammo for the weapon. He said he was struck by the ease of the transaction compared to the challenges he faced getting a gun.

"I guess you're allowed to buy ammunition without a background check or anything," he said. Bishop's assessment: "It was pretty easy."

While the crime Bishop is charged with committing is unusual, his casual bypassing of ammo restrictions might not be. A 2006 study that tracked ammunition in Los Angeles found that "prohibited possessors" bought more than 10,000 rounds of ammo at legitimate retailers over a six-month period. The study found that 2.6 percent of buyers, on average more than one in 50 people, was barred by law from owning ammunition.

"I'm not interested in entering a debate about banning firearms. It's not going to happen," said George Tita, the study's lead author and a criminology professor at the University of California, Irvine. However, he said, "We have an obligation to keep the firearms, ammunition — whatever anyone is not legally able to possess — out of possession."

Not everyone agrees that background checks are the sensible way to accomplish that goal.

"It's like saying you can't buy gasoline unless you have a car," said Marion Hammer, executive director of the National Rifle Association's state lobbying arm, the Unified Sportsmen of Florida. Hammer said requiring background checks for ammunition would be redundant, because the law already prohibits certain people from owning ammo.

She said requiring background checks for both ammunition as well as guns would be a strain for the state's law enforcement computer systems.

"We have enough laws on the books already without new laws and without overloading the system for ammunition," she said. She continued, facetiously, "Why don't we have background checks on people who want to buy steak knives?"

In Florida, gun background checks are processed through the Florida Department of Law Enforcement. Agency spokesman Keith Kameg said that each check takes about a minute. The total time it takes a retailer to call the department and receive a response, start to finish, is about four minutes, he said.

"It's a very simple law enforcement tool," Blumenthal said. "The burden is minimal to the government, and the gun shops, and to the individual."

Peter Jamison can be reached at pjamison@tampabay.com or (727) 445-4157.