“There is a feeling among all of us — from the administration to the Senate to us — that this is one of the priority subject matters for us to address this session. I do feel there will be some movement,” DeLeo said in an interview with the Globe last week. “We’ve got to do something about it.”

DeLeo did not speculate on how gun laws might change, but the outlines of a prospective House bill show that legislators are almost certain to reexamine restrictions on semiautomatic assault rifles, one of which was used in the Dec. 14 massacre in Newtown, Conn.

The weapons are banned in Massachusetts if manufactured after 1994, but that cutoff allows residents to own older versions and outfit them with high-capacity ammunition clips, lawmakers said. That loophole, similar to one in a federal ban that expired in 2004, is expected to draw close scrutiny from legislators.

“It’s still going to do the same job killing you,” said Representative David Linsky, a Natick Democrat and former prosecutor, who is planning to file a bill by Friday with about two dozen provisions to overhaul the state’s gun codes.

“There are so many loopholes in the Massachusetts law,” Linsky said. “We should not accept the level of restrictions we have and think we’re safe, because we’re not.”

Massachusetts is one of only seven states that ban semiautomatic assault rifles, which can fire bullets in rapid succession without reloading. If the rifle is equipped to handle a detachable ammunition clip, the firepower can increase exponentially.

State law also gives police chiefs wide discretion to deny permits to carry a concealed weapon if the applicant is not considered a “suitable person.”

DeLeo’s aides said the speaker welcomes Linsky’s work, which is expected to address wide-ranging concerns about gun design and licensing, including better access to mental health data for background checks. Linsky also wants to close a loophole that allows gun shows to sell weapons without checks, ban high-capacity clips, and require gun owners to purchase liability insurance.

“I think Newtown was another 9/11 moment. I haven’t seen this level of passion and support before,” Linsky said. “I know from my conversations with the membership that a majority of the House will support further tightening the gun violence prevention laws in Massachusetts.”

Governor Deval Patrick also will seek tougher gun restrictions this session, his aides said. In December, Patrick told reporters that the state should limit gun purchases to one a month and join the National Mental Health Registry to enhance background screening.

New York Governor Andrew M. Cuomo already has issued a fervent call for a comprehensive overhaul of his state’s gun control statutes, including a tighter ban on assault weapons.

Despite growing momentum to review the Massachusetts gun laws, any significant change is likely to face fierce opposition from the gun lobby, led in Massachusetts by the Gun Owners’ Action League.

Jim Wallace, the league’s executive director, argued that greater regulation in the wake of the Newtown massacre is not the answer to reducing gun violence.

“My question for the government is, where’s the problem?” Wallace said. “The reason this thing is so horrible, it’s because it’s so rare.”

Representative George N. Peterson Jr., the House minority leader, said that although gun owners such as himself are appalled by the Newtown shootings, he does not think further restrictions are needed.

“As tough as our licensing procedures are, it hasn’t done much to cut down on the gun violence in Massachusetts,” said Peterson, a Republican from Grafton. “Hopefully, cooler heads will prevail, and we will keep away from the rhetoric.”

Peterson said that the estimated 300 million firearms in the country — nearly one for every man, woman, and child — is not a problem in itself. “I don’t think that’s a bad thing,” Peterson said, “because we, as individuals, have the right to protect ourselves.”

DeLeo, however, said, “I don’t think this state, as a society, can sit back and do nothing.”