You may soon be barred from legally buying a rifle or shotgun in New Jersey until you turn 21.

The latest gun-control bill introduced by Democratic lawmakers in the New Jersey Legislature would raise the minimum age to obtain a permit to purchase either weapon in the Garden State from 18 to 21.

That would match up with current state law that requires people to be 21 to buy handguns from licensed dealers.

It's the latest in a string of bills sponsored by Democrats make New Jersey's already tough gun laws even tougher -- an effort that has increased in the wake of the Parkland, Florida, school shooting and other massacres.

The sponsors of this measure -- state Assemblymen Roy Freeman, and Andrew Zwicker, both D-Somerset -- said the goal is to prevent gun violence.

"There is no easy solution to the proliferation of gun violence in this country, but there are measures we can take to help keep people safe," Freiman said in a statement. "Bringing the rules on rifles and shotguns in line with the rules on handguns can help. If you have to be 21 to buy a handgun, the same standard should apply to rifles and shotguns."

But the bill (A3815) has some exemptions.

Anyone under 21 who already has an ID to purchase firearms in the state by the time the measure takes effect would be exempt.

So would anyone serving in the military or in law enforcement.

People under 21 would still be able to possess -- but not buy -- a handgun, rifle or shotgun if they are in the presence of a father, mother, legal guardian, or someone who holds a handgun permit or firearm purchaser ID.

The same goes if they use the guns for competition, target practice, instruction, training, or for hunting during the designated hunting season, as long as they have a valid hunting license.

Zwicker said they want to make it "harder for people with bad intentions from getting their hands on these weapons, but we also want to strike the right balance."

The lawmakers cited data from the FBI's Uniform Crime Report, which show 18- to 20-year-olds commit gun homicides four times more than those who are 21 or older.

"Research shows that the adolescent brain is still maturing in the teenage years, which is why teens often make decisions instinctively and without weighing the consequences," Freiman said.

But Scott Bach, a leading New Jersey gun-rights advocate, slammed the proposal, saying it would be "ignored by criminals and madmen, and will only be followed by honest citizens who are not the problem to begin with, and who ironically could be turned into victims by it."

"A single 18-year-old woman living alone would be actively blocked from defending herself in a home invasion by this bill," said Bach, the executive director of the Association of New Jersey Rifle & Pistol Clubs. "If you're old enough to vote, and you're old enough to be drafted, you're old enough to be able to defend your life with a firearm in an emergency."

Alexander Roubian, president of the New Jersey Second Amendment Society, said his groups has hundreds of young people and teenagers who compete in shooting sports and "have never committed crimes."

The bill would need to pass both the Assembly and state Senate -- each of which are controlled by Democrats -- and then signed by Gov. Phil Murphy to become law.

The Assembly last month passed seven bills to tighten the state's gun laws and the Senate is expected to vote on them in June.

Murphy, a Democrat who campaigned last year on more gun control, has vowed to sign them all.

Lawmakers also introduced a bill this month to ban untraceable homemade firearms known as "ghost guns" in the state.

Brent Johnson may be reached at bjohnson@njadvancemedia.com. Follow him on Twitter @johnsb01. Find NJ.com Politics on Facebook.