The school shooting in Connecticut that killed 20 children has changed the dialogue, Manchin said.
"I'm not afraid to say, 'Let's talk about that,'" Manchin told reporters during a conference call Monday. "I'm not afraid of the political ramifications."
"You have people who want to use scare tactics and extremes and try to drive a wedge when we're trying to have a dialogue," he said. "Don't you think we should at least sit down and talk about it?"
The comments by the West Virginia Democrat came on the day of the first funerals for the Sandy Hook Elementary School students killed Friday.
The massacre renewed calls from some Democrats for a ban on military-style assault weapons and a look at how the nation deals with individuals suffering from serious mental illness.
Manchin said school safety, movies and videogames that glorify violence should also be part of the discussion.
"This needs to have an adult conversation about the society we have become and the direction we are going," he said.
President Barack Obama traveled to Newtown, Conn., Sunday night to console the grieving families, the fourth such trip he's had to make during his presidency. He vowed
Gun control was a hot topic in the early 1990s, when Congress enacted a 10-year ban on assault weapons. But since that ban expired in 2004, few Americans have wanted stricter laws and politicians say they don't want to become targets of a powerful gun rights lobby.
"We can't be afraid to talk about it," Manchin said. "I'm not supporting a thing except open dialogue."
Manchin, who had been hunting with his family over the weekend, also said a 2010 campaign ad that showed him firing a hunting rifle at a paper target labeled "Cap and Trade Bill" did not glorify firearms.
"What we did at that time and the way we used it was in the most responsible manner. I'm a proud gun owner and I'm a responsible user and I don't think that glorified anything. It was not intended for that," he said.
Manchin is the most prominent gun rights advocate to speak publicly in the wake of the shooting.
Chris Feldhaus, a 31-year-old Republican from Charleston, W.Va., said he voted for Manchin in November but believed his latest remarks were an effort to win more support.
"I like what he does, but lately it seems like he's more of a TV guy wanting to be on TV more so than worrying about the issues," Feldhaus said.
Terri Roush, another Manchin supporter from Nitro, W.Va., said even if he was just trying to be in the spotlight, the issue deserved to be in the spotlight.
"So if he's the voice to do it, then by all means. I think he's somebody in West Virginia that people respect, people admire. I think it's something that needs to be brought to everyone's attention," she said.
Salcedo contributed from Washington. Associated Press writer John Raby in Charleston also contributed to this report.