The White House on Monday defended the Obama administration’s move to ban certain bullets used in a wildly popular rifle, a proposal that has stirred opposition from Second Amendment advocates and a prominent member of Congress.

The Bureau of Alcohol, Tobacco, Firearms and Explosives is considering a ban on M855 ball ammunition, which pro-gun groups have said is among the most popular cartridge used for the AR-15 rifle and is frequently used for sporting purposes like hunting, because of its so-called “armor-piercing” capabilities.

“It would be fair to say, as we are looking at additional ways to protect our brave men and women in law enforcement, and believe that this process is valuable for that reason alone,” White House press secretary Josh Earnest told TheBlaze during the press briefing. “This seems to be an area where everyone should agree that if there are armor-piercing bullets that fit into easily concealed weapons, that puts our law enforcement at considerably more risk.”

FILE - In this Wednesday, April 10, 2013 file photo Veetek Witkowski holds a newly assembled AR-15 rifle at the Stag Arms company in New Britain, Conn. The city manager and police chief in Maquoketa, Iowa are working on a new policy that would let officers use their own semi-automatic rifles, such as the AR-15, while on duty. The Dubuque Telegraph Herald reports the city would also set up a loan program to let officers buy rifles. (AP Photo/Charles Krupa, File)

AP Photo/Charles Krupa

“So I put this in the category of common-sense steps the government can take to protect the Second Amendment rights of law-abiding Americans, while also making sure that our law enforcement officers who are walking the beat every day can do their jobs just a little more safely,” he continued.

Current law provides exemptions for certain ammunition that could be considered “armor-piercing” bullets – such as the M855 – if the ammunition is primarily used for sporting purposes.

The proposal is open now for public comment at the ATF level.

Gun Owners of America spokesman Erich Pratt called it an attempt to do through executive branch regulation what the White House couldn’t get done in Congress.

“In 2013, the administration lobbied hard to get Congress to ban AR-15s and other similar semi-automatic rifles. But even in a Democrat-controlled Senate, anti-gunners could only muster 40 votes, a clear minority,” Pratt told TheBlaze Monday. “So the proposed ATF ban on M855 ammo is simply an attempt by the Obama administration to make an end-run around the Congress. After all, if it can ban a common cartridge that is used for the AR-15 rifle, then it can substantially drive up the cost of using the firearm.”

Last week, the National Rifle Association and Rep. Bob Goodlatte (R-Va.), chairman of the House Judiciary Committee, drafted a letter to ATF Director B. Todd Jones, saying the regulation being considered “does not comport with the letter or spirit of the law, and will interfere with Second Amendment rights.”

“ATF has now rescinded that exemption because repeating handguns that fire the M855 round are commercially available,” the letter said. “Yet this round is amongst the most commonly used in the most popular rifle design in America, the AR-15. Millions upon millions of M855 rounds have been sold and used in the U.S., yet ATF has not even alleged – much less offered evidence – that even one such round has ever been fired from a handgun at a police officer. The idea that Congress intended LEOPA to ban one of the preeminent rifle cartridges in use by Americans for legitimate purposes is preposterous.”

The ATF proposal states: “The firearm industry has developed commercially available handguns designed to use conventional rifle ammunition. This ammunition meets the content requirement of the definition, but previously was not classified as ‘armor piercing’ under the statute because there were no handguns that could ‘use’ it. As a result of the availability of these handguns, however, some conventional rifle ammunition now falls within the statutory definition and is properly classified as ‘armor piercing ammunition,’ despite the fact that the ammunition itself has not changed. Consequently, ammunition manufacturers have requested exemptions for this ammunition.”