White House Press Secretary Josh Earnest is defending a proposal by the Bureau of Alcohol, Tobacco, and Firearms to ban AR-15 ammunition. Earnest calls it a “common sense” approach.

“This seems to be an area where everyone should agree, that if there are armor piercing bullets available that can fit into easily concealed weapons, that it puts our law enforcement at considerable more risk,” Earnest explained when questioned about the ban by White House reporter Fred Lucas.

The proposed “framework” would ban the 5.56-millimeter “M855 green tip” rifle bullet to prevent the ammunition from being used in handguns. The ATF has requested public comment before making a decision.

Republican lawmakers have opposed the ban, submitting a letter to ATF director B. Todd Jones.

“Millions upon millions of M855 rounds have been sold and used in the U.S., yet the 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 letter reads.

Earnest said that the ATF was considering the ban via its “standard process” for such actions, and directed questions to the bureau.

The National Rifle Association vowed to fight the ban, asserting that the organization would work with members of Congress on legislation to stop the ATF proposal.

The potential ban has angered gun-rights advocates and is currently causing a run on the specific type of ammunition across the United States.