"You are using the pain of the victims of gun violence to speak in a way that allows you to look like you're going to do something but only to play games with their emotions," Fred Guttenberg said.
The number handed in is still only a tiny proportion of guns in the country, estimated to be between 1.2 and 1.5 million.
Amid calls for a ban on assault weapons after the shootings in El Paso and Dayton, one Twitter user posed a question that sparked a huge response.
The new ban takes effect April 12.
Beto O'Rourke, a potential 2020 presidential candidate, hailed the passage of a bill that would require background checks on all gun sales.
Representative Lucy McBath and allies in Congress, including Nancy Pelosi, are working for swift action in passing legislation to expand background checks. And that's just for starters.
My son, George Jr., was shot and killed in 2013. Trump's proposal will only make black and brown children like mine less safe.
Republican Kelli Stargel opposed a ban on assault weapons.
The former Congresswoman who was shot in 2011 spoke with Newsweek about the small steps she's made in both recovery and gun reform.
There are some holes in the conversation about mental health and its connection to mass violence.
Rather than doing the right thing and cleaning up its act, the gun industry turned to Congress for relief.