Congressional Democrats are pressuring the Obama administration to move ahead “swiftly” with a proposal that would ban a form of armor-piercing ammunition.



In a draft letter first obtained by The Hill, Democrats are urging the director of the Bureau of Alcohol, Tobacco, Firearms and Explosives (ATF) to use his “existing authority” to keep “dangerous ammunition out of our communities.”



“We hope that the Bureau will swiftly review comments on the proposed framework and issue a revised proposal that will address the danger posed by handguns that fire 5.56mm and other rifle ammunition,” Democrats write in the letter.



The ATF had sought to prohibit gun companies from manufacturing or selling 5.56 mm projectiles for M855 cartridges, arguing they are a threat to law enforcement officers because they can be used in handguns.



But the proposal generated a firestorm of opposition from Republicans and gun groups, who denounced it as an attack on the Second Amendment that could open the door to sweeping restrictions on ammunition.

With the backlash growing, the ATF backed down earlier this week, shelving the proposal indefinitely to allow time for “further study.”



House Democrats in their letter say they are “very disappointed” that the ATF delayed the rule. The proposal, they say, is true to the spirit of the Law Enforcement Officers Protection Act, which Congress passed in 1986 to ensure that officers do “not face extreme safety risk from firearm technology.”



“It is critical to update this legislation as new technologies are developed in order to keep law enforcement officers and our communities safe," they write. "That is why we urge you not to drag out this delay and to act swiftly to keep armor-piercing ammunition that can be used in handguns off the street.”



Dozens of House Democrats, including Reps. Carolyn Maloney (N.Y.), Jackie Speier (Calif.) and Steve Israel (N.Y.), are expected to sign the letter, which will be sent on Friday to ATF Director B. Todd Jones.



Jones declined to comment Thursday on whether his agency might reconsider the bullet ban at a future date, but he defended the plan as a "good faith effort" while testifying at a Senate hearing on the agency's budget.



"I want to make sure everyone understands that this was not — contrary to the blogosphere — an effort to completely ban that sort of cartridge,” he said.

While the ammunition has long been used by hunters in AR-15 rifles, the bullets can now also be used in handguns, which the ATF argues makes them a bigger threat to law enforcement officers.

Republicans and gun groups railed against the ATF proposal, calling it a “backdoor” attempt to restrict high-powered rifles, which are popular among hunters and sportsmen.



“A lot of us are troubled at the ATF’s process and intent regarding this proposed ban,” Sen. Richard Shelby (R-Ala.) said. “It’s concerning to many of us that the new federal firearms regulations referenced that.”



The National Rifle Association led the lobbying charge, helping to flood the ATF with more than 90,000 comments, most of them critical.



“NRA members fought back as the tip of the spear,” Chris Cox, executive director of the group’s lobbying arm, told The Hill.



House and Senate Republicans mounted a pressure campaign of their own, demanding in letters to Jones that the rule be withdrawn.



“If law-abiding gun owners cannot obtain rifle ammunition, or face substantial difficulty in finding ammunition available and at reasonable prices because government entities are banning such ammunition, then the Second Amendment is at risk,” said a letter signed by 53 Republican senators.



The White House declined Wednesday to weigh in directly on the bullet ban proposal, instead stressing that President Obama remains committed to reasonable gun regulations.

“The president’s commitment to putting in place common-sense rules that will protect Second Amendment rights, but also prevent those who shouldn’t have firearms from getting them, is as strong as ever,” White House press secretary Josh Earnest said.