WASHINGTON — The National Rifle Association said Sunday it opposes any legislation to ban the use of "bump stocks" on semi-automatic weapons — even as it has said some regulation may be necessary.

On Sunday morning talk shows, the gun lobbying group said the Trump administration, not Congress, should take action on the devices. Under the Obama administration, the Bureau of Alcohol, Tobacco and Firearms permitted the sale of the devices in 2010.

Bump stocks have taken center stage in the gun control debate after the Las Vegas shooter apparently used them last week to convert semi-automatic rifles into fully automatic weapons mimicking machine guns.

"It’s illegal to convert a semi-automatic to a fully automatic. The ATF ought to look at this, do its job and draw a bright line," NRA executive vice president Wayne LaPierre said on Face the Nation.

Allowing Congress to take action, LaPierre said, risks turning the bill into "some kind of Christmas tree" to advance other gun control measures that could impact both semi-automatic and automatic weapons. "If you fuzz the line, they're all at risk and we're not going to let that happen," he said.

But Sen. Dianne Feinstein, D-Calif., said Congress needs to close the loophole. She introduced a two-page bill last week that would ban bump stocks, trigger cranks or similar devices within six months, with an exception for government or military use.

"Regulations aren't going to do it. We need a law," Feinstein told Face the Nation. "It can't be changed by another president. Right now we're seeing one president change actions of a president that came before him, and that would happen in this area. And I hope that Americans will step up and say, 'Enough is enough. Congress, do something.'"

She said she has 38 cosponsors on such a bill — but all are Democrats.

House Speaker Paul Ryan, R-Wis., said last week that bump stocks are "something we need to look into." But conservatives in his conference are already saying they're opposed to legislation.

Rep. Steve Scalise — himself wounded by gunfire at a June 14 congressional baseball practice — told NBC's Meet the Presshe also opposes any congressional action on "bump stocks."

“Minority Leader Nancy Pelosi already said she wants it to be a slippery slope,” he said. “She doesn't want to stop at bump stocks. They want to go out and limit the rights of gun owners.”

The White House hasn't said where it comes down on that issue. "We'll be looking into that over the next short period of time," President Trump said Thursday.

Trump's statement came as police on Sunday said they found a note in the hotel suite of Las Vegas gunman Stephen Paddock that apparently showed the calculated distance from his window to the shooting victims below — as well as the trajectory of bullets from the height of his 32nd-floor room.

Members of the SWAT team that stormed Paddock's room noticed the note on a nightstand near his shooting platform, CBS' "60 Minutes" reported Sunday.