The gun used to unleash unimaginable carnage at a Connecticut elementary school a month ago was a Bushmaster semiautomatic rifle. It was equipped with a protruding pistol grip and a 30-round ammunition magazine, according to the Connecticut State Police.

Under Connecticut law, it was not considered an assault weapon.

The gun used to kill two firefighters in the Rochester suburb of Webster and wound two more was also a Bushmaster semiautomatic rifle. It, too, had a pistol grip and a 30-round clip, according to Webster police. A former neighbor of the shooter allegedly bought the gun for the killer – which was illegal because he was an ex-con.

That gun did not fall under New York’s definition of an assault weapon, although the magazine was banned.

But that changed earlier this week when a sweeping set of gun-control laws was enacted in reaction to the shootings in Connecticut and Webster.

The new state laws redefined such rifles and other semiautomatic weapons as “assault weapons,” banning them from being bought or sold in the state. The guns are not being confiscated, but owners must now register them.

Gun-rights advocates are furious over the new legislation and the use of the term “assault weapon.” That’s a scare tactic used by pro-gun-control politicians to push through tougher regulations, they say.

“What is that? Aren’t all guns assault weapons?” asked Rus Thompson, who heads New York State’s Tea Party and is organizing a “Gun Appreciation Day” rally in Niagara Square today that is expected to draw hundreds of gun-rights supporters.

So, what is an assault weapon?

Assemblyman Joseph R. Lentol, who helped negotiate and push through Gov. Andrew M. Cuomo’s bill, acknowledged that there’s some misunderstanding in the public about what defines an assault weapon.

“It’s a confusing term,” the Brooklyn Democrat said.

Under the new state SAFE Act, an assault weapon is now defined as a semiautomatic rifle or pistol with a detachable magazine and one or more military-style features.

Semiautomatic means that the trigger must be pulled for each bullet to be fired. Fully automatic weapons, which allow the user to fire continuously by holding the trigger down, have been banned in New York since the 1930s.

Semiautomatic shotguns with one military-style feature also are now categorized as assault weapons in New York.

For example, with semiautomatic rifles, the banned features would include a pistol grip, a folding or telescoping scope or even a bayonet mount. The same goes for semiautomatic shotguns with a military-style feature.

Previously, such weapons were banned if they had two or more such features – a state provision that mirrored the federal assault weapons ban that expired in 2004. New York’s “assault weapons” laws remained in effect.

All assault weapons, as newly defined in Cuomo’s legislation, are now illegal to buy or sell in the state. Anyone who owns such a weapon is allowed to keep it, but owners must now register anything categorized as an assault weapon with the state. They do not need to obtain a permit for them, as is required for pistols.

The new legislation also takes aim at high-capacity ammunition clips – only clips that hold seven or fewer bullets can be bought and sold in the state. Gun owners who had clips that can hold up to 10 rounds can keep them but cannot have more than seven rounds in the clip.

Under previous state and federal laws, clips that could hold more than 10 rounds had been banned from sale but were grandfathered into law. However, because there was no way to tell whether they were made or sold before 1994, the law was virtually impossible to enforce. The new legislation is aimed at closing that loophole.

The new laws also require background checks on all firearms buyers, including transactions between private parties.

Lentol said part of the confusion about the term “assault weapon” comes from people using the term interchangeably with “assault rifle.”

An assault rifle is an automatic weapon or one that can switch between single fire and multiple bursts that the military would use, Lentol said.

Assault weapons have been defined since 1994 as semiautomatic weapons with the detachable magazine and two military-style features, he said.

Cuomo and the Legislature changed the definition to one feature because “they are still assault weapons whether you have one feature or two features.”

Wilson Curry, an antique gun dealer who doesn’t sell what he calls “black guns” but owns an AR-15, a semiautomatic rifle, said the kinds of semiautomatic weapons that are now considered assault weapons are popular among hunters and target shooters.

“They’re high-end sporting rifles,” he said.

He explained that AR stands for “automatic rifle,” because when they were first invented, they were made for the military. But what’s been made available to the general public is strictly semiautomatic, meaning the trigger must be pulled to fire each bullet.

Jim Tresmond, a Hamburg attorney who is working with a group of lawyers across the state to file a lawsuit to stop the Cuomo’s new legislation, said that to him the term “is used to foster fear.”

He said: “Fear is a really emotional feeling in people. It’s basic, and if you can scare people half to death with language you are probably going to, let’s say, influence legislation one way or another. I think it’s just terrible.”

Harold “Budd” Schroeder, chairman of the Shooters Committee On Political Education, took issue with how the addition of military-style features makes a semiautomatic rifle an assault weapon.

“What it breaks down to is what I call Ugly Gun Syndrome,” Schroeder said. “I don’t know how [putting a feature on it] makes any rifle more deadly without it on.”

Connecticut State Police Lt. J. Paul Vance, who handled the news conferences in the wake of the Newtown shootings, told The Buffalo News that to him, it doesn’t matter what the gun that accused shooter Adam Lanza used is called or how it is categorized.

“It did a tremendous amount of damage,” he said. “That’s all they really need to know.”