WASHINGTON – Rep. Mike Ross, a leading gun rights advocate on Capitol Hill during 12 years in the U.S. House, threw his support Wednesday behind efforts to ban high-capacity assault weapons in the aftermath of the Sandy Hook school massacre.

"This is not the same America that I grew up in, and I think it is time to address whether there really is a legitimate need for high-capacity weapons that can shoot, you know, a lot of rounds of ammunition," said Ross, co-chairman of the Congressional Sportsmen’s Caucus.

Ross, a Democrat, said during an interview that he has given a lot of thought to this change of heart.

"I think past notions that any change at all in gun laws is a foot in the door – I think it is time we get beyond that," he said. "America has changed. Unfortunately, it is a different place than when we were children. And, we need some commonsense reforms."

As an outgoing member of Congress, Ross won’t be around in the 113th session to vote on gun legislation drafted in response to the Connecticut shooting rampage that left 20 children and six educators dead. However, his turnabout does demonstrate how the tragedy has substantially shifted the balance toward substantive gun law reforms.

Rep. Mike Thompson, D-Calif., a former co-chair of the Congressional Sportsmen’s Caucus, has also said that gun control should be part of a comprehensive response to the shootings. Rep. Jack Kingston, R-Ga., who has enjoyed strong support from the National Rifle Association, as has Ross, has also joined the chorus.

Along with gun reforms, they say Congress should consider reforms of the mental health system and look at regulating graphic violence in video games.

Rep.-elect Tom Cotton, a Republican from Dardanelle, said Wednesday that Congress should focus on the mental health system in response to the massacre at Sandy Hook Elementary School. He is opposed to any new gun regulations, saying that there are "enough already on the books."

President Barack Obama said Wednesday that he plans to submit broad new gun control proposals to Congress by the end of January.

Ross is a lifelong member of the NRA and in the past has been a key champion of Second Amendment rights.

"No one is more pro-gun than I am. No one enjoys hunting more than I do," he said.

In 2010, Ross led a group of 65 pro-gun Democrats in denouncing comments by U.S. Attorney General Eric Holder that the Obama administration intended to reinstate the assault weapons ban that expired in 2004.

Ross introduced legislation last year to repeal the D.C. semiautomatic gun ban and make it easier for residents of the nation’s capital to purchase and keep guns in the city.

The Newtown shooting appears to have been the last straw for Ross when it comes to civilian ownership of weapons designed for combat.

"These weapons that have been used in these horrendous slayings aren’t the type of guns I hunt with or anybody else hunts with. I mean when you duck hunt you can only have three shells in your gun by law. And, you know, I shoot a Browning 270 deer rifle. I think it might hold four rounds — that’s it. And, I’m your typical hunter out there," Ross said.

The Newtown shooter used a .223-caliber Bushmaster rifle, a modified civilian version of the military’s M-16.

Since 1982, there have been at least 62 mass murders carried out with firearms in 20 states from Massachusetts to Hawaii. Most of the 142 guns used in the shootings were obtain legally, including dozens of assault weapons and semiautomatic handguns, according to a Mother Jones report.