The bill, patterned after laws in New Jersey and California, forbids the sale of certain guns after Jan. 1, 1994, except to a licensed dealer. The list includes rapid-fire guns with large magazines like the MAC-10 semiautomatic pistol, the Ruger Mini-14 assault rifle and the Uzi machine pistol, which the police in cities like Bridgeport say are turning up more frequently in the hands of drug gangs.

Residents who possess such weapons prior to July 1 could keep them, but would be required to register with the state police. The bill also sets a five-year prison term, in addition to any other sentence, for a person who commits a major felony with a banned gun. Bipartisan Coalition

In debating those provisions, like those about Colt, Republicans were in some cases as bitterly divided as Democrats. One Republican who supported the ban, Senator William A. Aniskovich of Branford, said he embraced the proposal after opening his mind and rejecting what he termed the unthinking assumptions of the past.

"I don't think I've every been called unthinking," snapped the Republican leader, Senator M. Adela Eads, in rising to oppose it.

From the day last month when the gun bill survived a pivotal vote in the Judiciary Committee, its fate has been tied to a fragile bipartisan coalition of urban Democrats and suburban Republicans in the Senate.

The first question was whether the coalition would hold up under a barrage of constituent calls, organized by the National Rifle Association and local gun-owner groups, that began immediately after the committee vote. Several senators said this week that they had received 800 or more calls on the bill in the last 10 days. Twenty to thirty messages on a senator's home answering machine every night became the norm.

But in the last days before the vote, the larger arguments of the N.R.A. -- that the bill was a meaningless gesture that would not affect urban crime and would only penalize honest gun owners -- appeared to recede before the concerns of local politics, and once again the coalition was under siege.

"This place is incredibly sensitive to the 'jobs' buzzword, and for good reason," said Mr. Aniskovich, who voted for the gun ban. "But it's having a peculiar effect on this bill."