House Speaker Ron Mariano said the latest bill penned by Judiciary Committee Co-chair Rep. Michael Day is “significantly different” than one he unsuccessfully tried to advance over the summer, when gun owners groups mounted vociferous opposition and some representatives appeared to balk.

“I think the chairman and his committee responded to the criticisms they’ve heard, tempered some of their perceptions, and I think we’ve arrived at a place which makes the commonwealth safer,” Mariano said.

But the changes appear not to have won over some of the legislation’s strongest critics.

“All they did was take a toxic bill and make it a little less toxic. That’s all,” said Jim Wallace, executive director of the Gun Owners’ Action League.

Although Senate Democrats have also signaled they want to enact some kind of gun reform legislation this term, Mariano and his team are poised to circumvent the traditional joint committee process used for most bills.

Day will lead a public hearing on Tuesday alongside House members of the Judiciary Committee and the House Ways and Means Committee. Officials appear not to expect any participation from senators, who have also been huddling privately to assemble gun law changes without the benefit of public hearings.

The House-only hearing is an unusual step: since 2007, the House Ways and Means Committee has only advised a single hearing without its Senate counterparts, and it was to solicit written testimony about police reform in July 2020.

The House Ways and Means Committee will then advance the bill to the floor, officials said. Rep. Aaron Michlewitz, the committee’s chair, said his panel already has in its possession the legislative vehicle it will use but declined to elaborate.

“We’re still working on that,” Michlewitz said.

Twenty-seven bills are currently pending in the House Ways and Means Committee, including several spending proposals and measures dealing with agriculture equity, septic regulations, pesticides, identification cards for homeless individuals, land transfers and MBTA safety. None appear to deal directly with firearms.

Mariano said he plans to introduce the bill for a House vote “later in the month,” and told reporters he wants to move forward “because we’ve invested so much time in this bill.”

He described growing concerns about ghost guns — an issue that law enforcement officials including Attorney General Andrea Campbell have raised — as the “main impetus,” and said Massachusetts needs additional changes to its laws in the wake of the U.S. Supreme Court’s Bruen decision last year.

House Democrats made multiple references Thursday to a shooting in Holyoke that occurred Wednesday, where a pregnant woman riding a bus was struck by an errant bullet. Her child did not survive, and suspects involved have been charged with murder, according to the Boston Globe.

“A woman minding her own business and sitting on a public bus midday in Holyoke now has a baby ripped away from her, and she’s left battling for her own life because of stray gunfire,” Day said. “This came within an hour of Holyoke police reporting that they’ve logged 113 instances of gunfire in the past six months alone. Make no mistake: we are in the midst of a national public health crisis due to gun violence, and it is relentlessly continuing to claim lives here in Massachusetts and across the country.”

Lawmakers have not held any public hearings on the original Day bill, the updated version, or an array of gun law changes offered by other lawmakers. Day went on a statewide, 11-stop “listening tour” to solicit feedback from interested parties before filing his first draft of the legislation.

Wallace said his group was not contacted or involved in the process of redrafting the bill, describing it as taking place “completely behind closed doors.”

“I’ve had a career in amending bills and making them palatable while also addressing the issue they’re trying to address, and I can’t with this one. There’s no issue to address and the language is so bad, there’s no way to fix it,” Wallace said. “You’d have to start from scratch.”

Day highlighted a trio of topics on which the redrafted legislation takes a new approach: serialization requirements, the assault weapons ban and prohibiting firearms in certain spaces.

In an attempt to limit the spread of homemade firearms that can be difficult to trace, the original bill called for all lower receivers — which are the main parts onto which most other gun pieces are attached — as well as barrels to be registered and stamped with a serial number.

The updated version eliminates barrels from that requirement, instead mandating only that the frame or receiver of a firearm to bear a serial number. Day said the change addresses concerns from gun owners and dealers about “the efficacy and the practicality of serializing the barrel of a long gun or a handgun.”

“All homemade receivers will be serialized,” Day said. “Coupled with our existing firearms regulation requirements and registration requirements, these changes will modernize our approach … and give our law enforcement professionals the tools they need to combat the rise of trafficking ghost guns.”

Like the original bill, the revision would overhaul the definition of assault weapons that are banned in Massachusetts, naming specific models as well as making clear that certain types of semiautomatic weapons with modifications are prohibited.

But the latest version newly includes a grandfather clause, exempting “assault-style firearm[s] lawfully possessed within the commonwealth on August 1, 2024” from the ban so long as the owner or seller is properly licensed.

“We heard from dealers and owners that outlawing some of these firearms immediately would effectively constitute a government taking of their lawfully owned property, so we’ve updated this proposal with a legacy clause,” Day said.

Both versions would prohibit carrying a firearm in government buildings, polling places and schools, and the redraft scales back the degree to which that ban would apply to private property.

Day’s first bill would have made it illegal to bring a gun onto “any private property, including but not limited to residential, commercial, industrial, agricultural, institutional or undeveloped property, unless the owner has provided express consent.” The updated legislation narrows that to “any private, residential dwelling of another, not held open to the public,” where an owner has not given consent.

“We now make clear that an individual must receive permission before bringing a gun into somebody’s home,” Day said. “We leave untouched the ability and the right of a business to declare that they do not welcome firearms on their own.”

Mariano originally wanted the bill to win House approval in the summer, but after a series of private meetings with representatives, he pushed the timeline back to the fall. While Democrats worked on changes, the bill’s opponents erected lawn signs up in cities and towns  around the state.

Senate Democrats wanted the legislation to be reviewed by a different committee than the House proposed, leaving Day’s original proposal in procedural limbo. Senate leadership is working to craft its own gun reform bill, but an aide to Majority Leader Cindy Creem said this week it’s unclear when a bill would be drafted.

One of Creem’s aides was in attendance Thursday as Mariano, Day and Michlewitz discussed their bill with reporters.

Senate President Karen Spilka said Thursday she is “happy” the House plans to take up its own gun bill.

“I believe Massachusetts should always have the strongest gun safety laws in the country. We’ll make sure that whatever gun safety bill that we pass will continue to make us, and ensure that we stay among the strongest,” she said in an interview on WBUR’s “Radio Boston.” “And we will pass it and I do believe we will have something on the governor’s desk, definitely before the session’s over. So I’m looking forward to that.”

John Rosenthal, chairman of Stop Handgun Violence, a Massachusetts based non-profit, said the bill would close “dangerous loopholes” and “help keep guns out of the hands of people who are legally prohibited from buying firearms.”

“This common sense gun violence prevention bill would also ban untraceable ghost guns, simplify and improve upon existing laws such as our assault weapons ban, and expands protections related to the Extreme Risk Protection Order and carrying firearms in sensitive places. These bills will absolutely save lives and endless grief without any inconvenience to law-abiding gun owners like me,” Rosenthal said. “They will also continue to make Massachusetts the safest state with the most effective gun violence prevention laws and lowest gun death rate in the nation.”

Rina Schneur, a volunteer with the Massachusetts chapter of Moms Demand Action, said recent shootings have shown that “gun violence remains an urgent crisis in Massachusetts.”

“While we are still reviewing this updated proposal, we are pleased by our leaders’ steadfast commitment to ensuring that Massachusetts remains a national leader in gun violence prevention and makes all Bay Staters safer,” Schneur said.