(WTVO) —  A gun-rights group says it is teeing up a lawsuit to block a new law that bans several guns that the state of Illinois now deems “assault weapons.”

Dan Eldridge with Federal Firearms Licensees of Illinois and Maxon Shooter’s Supplies in Des Plaines said he and at least one other group will seek immediate relief from the courts.

“It’s not going to last,” Elridget told The Center Square after the bill was passed. “We will win, and when we’re done with this, we’ll have an energized membership base, we’ll have a pretty big war chest and we’ll go after everything else that we can.”

Gov. J.B. Pritzker signed the bill Tuesday night, a measure that bans the future sale of about 100 different semi-automatic pistols, shotguns, and rifles because they are now considered assault weapons. Long-gun magazines with more than 10 rounds and handgun magazines with more than 15 rounds are also now illegal in Illinois.

The Illinois State Rifle Association has also promised to file suit.

“Challenge accepted,” ISRA Executive Director Richard Pearson said in a statement. “The Illinois State Rifle Association will see the State of Illinois in court.

The law allows owners of certain semi-automatic guns to keep them but the weapons must be registered by Jan. 1, 2024. Violator can be charged with a Class 2 felony.

State Sen. Darren Bailey, R-Xenia, says he and other gun owners will not follow the law because it’s unconstitutional.

“I and millions of other gun owners in this state will not comply,” the Republican from downstate Xenia said Monday on the Senate floor. “You’ve got to know that the actions that you’re taking right now are tyrannous.”

Bailey said the Second Amendment protects ownership of all firearms, even ones that weren’t invented at the time of its drafting.

Gun shop owners argue that true assault weapons–ones used by the military– are already illegal. They are automatic machine guns like the M16 and the AK47, which were banned by the federal government in 1986.

The new law now lumps all semiautomatic weapons like the AR-15 in with machine guns, which shop owners say has never been a fair comparison.

“The AR-15s that we sell here legally, as of right now, are not assault weapons in a sense,” said Brad Miller, who runs FlashPoint Firearms in Roscoe, Illinois. “They may look like it, but they’re not. It’s one trigger pull, and one round comes out of the gun.”