Three Republican members of Congress are gathering support to ask the ATF to undertake a new review of bump stocks, the type of gun modification used by the Las Vegas shooter to make his weapons fire at speeds similar to machine guns.
Asking other House members to sign onto a letter to the ATF seeking a new review, the three former military Republicans argued "fully-automatic weapons were never intended for civilian use."
The letter they plan to send this week to ATF also points out that members of Congress are thinking about passing new laws to address the bump stock modifications.
It won't be just Republicans - Rep. Ed Perlmutter (D-Colorado) plans to sign his name on the letter, his office tells 9NEWS.
Perlmutter asked President Obama's ATF to use its regulatory power to block the sale of bump stocks back in 2013. The agency argued it didn't have the legal authority.
That decision rested in large part on the way the mechanisms work - which involves pushing the shooter's finger back into the trigger rapidly by using the force of the gun's own recoil.
The ATF has a lab in West Virginia which regularly tests new gun technology for manufacturers who want to sell it. The agency has rejected other devices that make semi-automatic weapons fire in a manner similar to machine guns.
Just last month, the agency rejected a product called the "auto glove," which used an electric motor to repeatedly press a gun's trigger.
In its rejection letter, the ATF argued that the device essentially replaces the stock trigger on a gun and therefore is a "machinegun" under federal law and cannot be sold.
The agency also told the manufacturer that it couldn't return the device to its maker because of its illegal nature.
The ATF's legal view of bump stocks hasn't changed since 2010 when it reviewed an application to sell them under the "Slide Fire" brand name.
A group of nine Republican sent a letter asking the ATF to review the issue last week.
As of now, we don't know whether the new administration or the attack on Las Vegas have changed the agency's legal interpretation.