DES MOINES, Iowa — Joe Biden is calling for a cultural shift around how the country thinks about gun ownership.

"The Second Amendment — no amendment is in fact absolute," Biden told the Everytown for Gun Safety Action Fund's Presidential Gun Sense Forum Saturday in Des Moines, Iowa.

"You cannot stand up in this hall and yell fire. That's not freedom of speech because they know the consequence of yelling fire: There'll be a stampede, and someone will get hurt," the former vice president said.

The national conversation regarding gun control should extend beyond regulating who can buy a firearm to, for example, the effect violence can have on survivors, Biden told the audience. He added he was starting to see dialogue evolve in that direction, creating "a movement" toward change after so much gridlock in Congress.

"Folks, don't apologize at all about the Second Amendment," Biden advised, explaining how the amendment allows for limitations on who can own a weapon and what type. "These guys will tell you, the tree of liberty is watered with the blood of patriots. Give me a break."

“Can you go out and buy a flamethrower? Can you go out and buy an F-15?” he added. “If you want to protect yourself against the federal government, you’re going to need at least an F-15.”

Biden is one of 17 White House hopefuls addressing the forum, scheduled after twin shootings last weekend in El Paso, Texas, and Dayton, Ohio, while most of the primary field is in the state for the Iowa State Fair. The attacks claimed the lives of 31 people.