Trump administration moves to try and effectively ban bump stocks

President Donald Trump tweeted Friday that his administration will ban bump stocks devices that "turn legal weapons into illegal machines" and blamed former President Barack Obama for allowing them in the first place.

His tweeted comments come a day before student and teen-led nationwide marches calling for gun policy reform.

Attorney General Jeff Sessions in a statement on Friday announced the Department of Justice has begun the process to amend federal firearms regulations to clarify that bump stocks should fall under the technical definition of "machinegun" under federal law. Such devices "allow a shooter of a semiautomatic firearm to initiate a continuous firing cycle with a single pull of the trigger".

The announcement comes a month after the president directed the agency to work on a ban in the wake of a deadly shooting at Marjory Stoneman Douglas High School in Parkland, Florida which resulted in the deaths of at least 17 people and left 14 injured.

Bump stocks came under intense scrutiny after it was learned they were used in the Las Vegas mass shooting last year that left 58 people and hundreds of others injured.

The legal firearm attachments are designed to allow semi-automatic rifles to mimic the actions of a rapid-fire, fully-automatic weapon.

In 2010 the Bureau of Alcohol Tobacco and Firearms determined that it could not regulate bump stocks unless Congress changed the laws. Critics of the president's new push think any effort to reverse that ruling will be challenged in court.

Sen. Diane Feinstein, D-Calif, who has proposed legislation to ban bump stocks and semi-automatic rifles, has said she believes a legal challenge would ultimately be successful.

"The ATF currently lacks authority under the law to ban bump stocks," Feinstein wrote in February 20 statement.

"If ATF tries to ban these devices after admitting repeatedly that it lacks the authority to do so, that process could be tied up in court for years, and that would mean bump stocks would continue to be sold."

"Legislation is the only answer," she said.

The actions taken Friday by the Justice Department effectively open a rule change for public debate.

Following the school shooting at Marjory Stoneman Douglas High School in Florida last month, National Rifle Association spokesman Dana Loesch told ABC's This Week that the organization doesn't support a bump stock ban.

"The NRA doesn't back any ban, the NRA has asked the ATF to do its job and make sure that these classifications are consistent," Loesch told ABC's George Stephanopolous.

Sessions said the Justice Department will begin a public comment period on a proposed rule "that would define 'machinegun' to include bump stock-type devices under federal law-effectively banning them."