The speaker of the House also told CNN's Wolf Blitzer on "The Situation Room" that he was not planning on actively fundraising for Donald Trump's cash-strapped campaign, and that he saw possible agreement between his pro-trade message and Trump's protectionist sympathies.
But the sit-in that began earlier in Ryan's chamber earned his scorn.
"This is nothing more than a publicity stunt," Ryan said, saying House Democrats would infringe on Second Amendment rights and do nothing to prevent terrorist attacks. "This is not about a solution to a problem. This is about trying to get attention."
Ryan said they would not take up gun bills that the Senate already voted down on Monday. He called on legislation to be drafted in a "calm and cool manner,' not through sit-ins.
Rep. Chris Van Hollen, a Maryland Democrat, said Ryan's comments were "disrespectful to the nation."
"The speaker should come forward with his own proposals," he told CNN's Erin Burnett on "OutFront" Wednesday night in a phone call from the House floor.
Ryan also defended the lack of cameras broadcasting the sit-in, saying it was normal procedure when the body is in recess.
Ryan has had a tense political relationship with Trump, but he said he did not watch Trump's framing speech against Hillary Clinton delivered earlier Wednesday. While he heard it was received positively, Ryan largely declined to wade into its merits -- though he did say the thrust of Trump's critique is legitimate.
"I think people are a little Clinton scandal-fatigued in this country," Ryan said. "It is totally fair game that he questions those things."
Ryan, a prolific Republican fundraiser, said he was not planning to help fundraise for Trump's campaign, which raised new alarms this week with a low cash-on-hand figure. Ryan said he would only focus on raising cash for House Republicans, which he defended as in line with precedent.
"The leader of the House helps the House, just like the leader of the Senate helps the Senate," Ryan said. "The nominee is the one who is typically the draw -- not the other way around."
The speaker, who is chairing this summer's Republican convention, said he was "not signaling anything to delegates" about whether they should feel free to vote their conscience and against Trump if they so chose. Members of Congress, however, should feel free to do so, he reiterated.
Asked if he trusts Trump, Ryan initially chuckled before saying that "it depends on the issue."
Ryan also tried to close the gap between his support for Trans-Pacific Partnership, a massive trade deal pushed by the White House, and Trump's opposition to it. He said both of them favored good trade deals, and agreed that the Obama administration had "screwed up" on some key elements.
"He says he wants great trade agreements. I also want great trade agreements," Ryan told Blitzer.
Ryan signaled that he and Republicans on Capitol Hill would check Trump's more controversial proposals, such as his ban on Muslim immigrants.
"If you want to change a law, you have to pass a law," Ryan said. "Presidents don't write laws. Congress writes laws."