“I said from the beginning it’s important for us to act quickly, but it’s more important to act intelligently,” said Brendan Sharkey, a Democrat and the House speaker. “It’s also critical that we send a message to Washington and the rest of the country that this is the way to get this job done, to do it in an effective, meaningful and thoughtful way and to do it on a bipartisan basis.”

Lawrence F. Cafero, the Republican House minority leader, said the legislation was drafted with the intent of balancing the rights of hundreds of thousands of gun owners with the public safety needs of the state. Asked how much support it would have among Republicans, he said, “Substantial.” Asked if it would be a majority, he did not answer.

But Robert Crook, executive director of the Coalition of Connecticut Sportsmen, said: “Whatever gun legislation they pass is not going to have an impact on anything that happened at Sandy Hook. The problem there was the individual and the mother.”

He said he had not seen all the elements of the bill, but took issue with the provisions to add more than 100 new assault weapons to those banned by the state. Connecticut is one of only a handful of states that already has an assault weapons ban. Immediately after the bill is passed, the weapons on the expanded list could no longer be sold in Connecticut. Existing weapons would have to be registered with the state. Mr. Crook criticized lawmakers for failing to allow for more public discussion about this issue. “It’s being stuffed down our throats,” he said. “And the gun owners are going to suffer in this state.”

In some cases, the legislation would fill holes in the state’s regulations. Under the proposed legislation, all firearm sales, including those at gun shows, would require criminal background checks. Currently, the sale of any pistol or revolver, and the sale of a rifle or shotgun by a licensed dealer, requires a criminal-background check.

The legislation also breaks new ground. Legislators said that the provision that would mandate that weapons offenders be registered was the country’s first statewide measure of its kind.

The legislation would also mandate a new state-issued “long-gun eligibility certificate,” which would require that applicants take a firearms safety course, be fingerprinted and undergo a national criminal background check before buying any rifle, shotgun or ammunition.