AUGUSTA — Maine lawmakers took public testimony Wednesday on several firearms-related bills, including one to ban bump stocks and another to better define machine guns.

Supporters of the bump stock ban say 15 other states have already done so and they believe it will help prevent mass shootings in which gunmen use rapid-fire devices.

“Because these devices turn semi-automatic weapons into fully automatic machine guns, they create significant law enforcement and public safety concerns,” said Sen. Anne Carney (D-Cape Elizabeth). “Outdated laws that lag behind technology make devices to increase a firearm’s lethality cheap, easy to acquire and also able to skirt the laws like ours that ban machine guns.”

Carney is introducing a bill to ban bump stocks that is similar to one vetoed by Gov. Janet Mills last year. In her veto letter, Mills criticized the bill for “broad and ambiguous language.”

Carney told fellow members of the Judiciary Committee Wednesday that she has more narrowly tailored the bill to target “things that operate like machine guns.”

But opponents say new regulations will only punish those who already follow the law.

“These bills attack the rights of all gun owners, making criminals out of the left, the right and the middle,” said Robert Duhaime, a member of the Gun Owners of Maine.

Other bills considered Wednesday seek to ban so-called “ghost guns” which are guns assembled from kits and 3-D printers. The bill, LD 1126, also requires serial numbers on all firearms.

Another measure proposes to prohibit large capacity magazines.

In the afternoon, the committee was scheduled to take testimony on a bill to standardize laws regarding the carrying of concealed handguns in state parks, changing an employer’s ability to prohibit an employee from storing a firearm in a vehicle and eliminating the duty to inform law enforcement when carrying a concealed handgun without a permit.

The Judiciary Committee will vote on the bills in the coming weeks.