Changes to existing law or new laws can prompt the agency to reclassify an item, as can alterations to the device or weapon.
This week's massacre in Las Vegas brought one particular gun accessory into the spotlight.
The NRA, which famously opposes virtually any hint of new restrictions called on ATF "to immediately review whether these devices comply with federal law". A bill in the House from Rep. Carlos Curbelo, R-Fla., is expected soon. Ryan said that it hasn't been scheduled for a floor vote yet. "And I'm an avid sportsman".
"This is definitely an area we should look at", House Majority Leader Kevin McCarthy told the Fox News Channel. It's called the bump stock, and it's a device that some gun owners use to modify semiautomatic rifles to make them fire faster, nearly as fast as a fully automatic rifle.
She also urged President Donald Trump to finally display some positive leadership qualities.
JERRY MICULEK: All right, let's see if we can light up this gizmo here.
"In Las Vegas, reports indicate that certain devices were used to modify the firearms involved", the NRA said. It's something we're very open to.
"It's too early" since the massacre to address gun control, one Senate Republican warned.
On Wednesday morning, House Democrats, led by House Minority Leader Nancy Pelosi, D-Calif., Rep. John Lewis, D-Ga., and former Rep. The goal here is to prevent illegal weapons or weapons that perform as illegal weapons. "To me, that is part of that same type of process".
"I think they should be banned".
The Obama administration's ATF gave its seal of approval to selling the devices in 2010 after concluding that they did not violate federal law.
These devices are legal becuase they don't actually make a gun automatic.
Democrats should hold Republicans to that - take the information we learn over the coming days in the investigation and push for legislation to make it harder for someone else to do what this week's shooter did.
Legislators of both parties have suggested bump stocks should be controlled more tightly or banned altogether. "So we'll see what kind of legislation is proposed".
However, Las Vegas Sun reporter Adam Candee, who has been covering the latest shooting, told RNZ's Morning Report discussion had already settled into a familiar cycle. Judiciary Chairman Chuck Grassley, R-Iowa, has expressed reservations about moving too quickly and told Politico he was anxious about starting down a slippery slope of gun legislation.
This is one of the examples gun rights advocates point to, stating that shooters will find a way to get their hands on guns legally or illegally. Families are grieving; the country is grieving. But a bump stock sells for several hundred dollars, and can be installed on the weapon easily. Gun control! When do we want it? You go out to the desert out here, and you can shoot high speed and just have a good time with it.
Still, that is a small issue in the overarching gun control debate, experts noted.
Lewis, the civil rights icon who led the gun control sit-in on the House floor past year after the Pulse nightclub shooting in Orlando, approached House Speaker Paul Ryan, R-Wis., on the House floor last night, seeking his cooperation for the Wednesday demonstration.
Politico reported Thursday that bump stocks are banned at the firing range at NRA's headquarters.
Meanwhile, GOP legislation aimed at loosening gun rules faces an uncertain future.