Republican lawmakers are taking aim at the $200 federal tax on firearm suppressors, tucking a provision into a massive 400-page tax bill that would scrap a requirement dating back to 1934.

The measure spans just twelve lines but would end the longstanding tax requirement for purchasing suppressors, which are devices sometimes referred to as silencers in popular culture.

Some 4.5 million suppressors are currently registered with the government, according to industry group National Shooting Sports Foundation. Buyers typically shell out around $830 for a suppressor at retail, in addition to the $200 tax stamp.

Eliminating the tax would cost the federal government roughly $1.4 billion over the next decade, according to estimates from the Joint Committee on Taxation.

“This is about making sure that people keep their hearing at the end of the day,” Representative Eric Burlison, a Republican from Missouri, said in an interview, adding that he questioned whether the tax violates the Second Amendment.

Burlison worked alongside Representative Rudy Yakym, a Republican from Indiana, on the suppressor tax elimination. They opted to leave changes to short-barrel rifle taxation for another day after committee members raised concerns.

Democrats tried and failed to strip the suppressor provision during a late-night markup session last month. “As a combat veteran, a lifelong hunter and gun owner, I can tell you this has nothing to do with hearing protection, but everything to do about making money for one segment of the gun industry,” Representative Mike Thompson, a Democrat from California, said of the bill.

But the American Firearms Association was not entirely pleased with the limited scope of the legislation. American Firearms Association vice president Patrick Parsons dismissed the change as "nothing more than a crumb dropped from the King’s table.”