WASHINGTON – Rep. Erik Paulsen, who usually votes against additional restrictions on the sale of firearms, is drawing criticism from Minnesota gun control opponents by co-sponsoring legislation to ban a device that allows semi-automatic rifles to fire at the rate of machine guns.

Paulsen, a Republican, has added his name to a proposal in Congress to ban the sale, manufacture and use of the devices known as bump stocks. The gunman in the deadly Las Vegas shooting this month used bump stocks as he fired on a crowd near Mandalay Bay Resort and Casino, killing 58 and injuring hundreds more in the worst mass shooting in recent U.S. history.

Paulsen declined an interview request from the Star Tribune for this story, and his office declined to provide further information about his decision to get behind the proposal first put forward by Sen. Dianne Feinstein, a California Democrat. In an interview this month with KSTP-TV, Paulsen said such a ban "seems to be reasonable, responsible and a response not only to the tragedy but going forward."

But Cory Birkemeyer, a Plymouth resident who belongs to the Minnesota Gun Owners Caucus and has previously voted for Paulsen, said he'd be opposed to such a ban.

"No gun control law would have prevented the tragedy in Las Vegas, so this bill only amounts to political grandstanding," said Birkemeyer, a risk management professional. He said he fears that the proposal is written so broadly that it would criminalize triggers and other aftermarket products that people legally purchase to modify their guns.

The House measure has 25 cosponsors, about half Democrats and half Republicans.

As a Republican in a swing district that went for Hillary Clinton, Paulsen has faced scrutiny from both sides for his positions in recent months. His fellow Minnesota Republicans, Reps. Tom Emmer and Jason Lewis, have not come out in support of banning bump stocks.

Paulsen's support for the measure has earned the praise of Protect Minnesota, a nonprofit that advocates for stronger gun control laws.

"We think it's great — it's wonderful," said the group's executive director, the Rev. Nancy Nord Bence. "He's a little late to the party, but terrific."

But Bence said she's more concerned that Paulsen could also still support several Republican-sponsored measures that were delayed following the Las Vegas massacre. One would allow reciprocity between states for concealed-carry permits; another would loosen regulations on buying gun silencers.

Bence maintains that those measures affect far more people than bump stocks.

"Otherwise it's just a political vote," she said. "He's not actually … saving lives."

Paulsen has been backed by the National Rifle Association, which usually opposes stronger gun restrictions.

"We were shocked by it," said Robert Doar, political director of the Gun Owners Caucus. "And particularly what was surprising was that the language of this bill is so loose."

Doar acknowledged that a good number of his group's membership don't think there's a legitimate reason to own a bump stock, because the devices reduce the shooter's control of the gun and ability to accurately hit a target while wasting a lot of ammunition.

"But we just have a hard time reconciling that banning any hardware is going to limit mass shootings," he said.

Maya Rao • 202-662-7433