Democratic Attorney General Maura Healey is warning gun dealers and manufacturers in Massachusetts against selling banned assault weapons, including what she described as copycat weapons.Healey said Wednesday her office is stepping up enforcement of the state's assault weapons ban following the mass shooting at a gay nightclub in Orlando, Florida, last month that claimed the lives of 49 patrons.The announcement prompted many gun dealers to head to their favorite shop to purchase a firearm. At the Four Seasons shop in Woburn, there was a line out the door. "We saw the email from Carl who said they wouldn't be able to sell them after today," Bruce Sterling said. "It seemed like it made a lot of sense to come and get an AR-15 today." Healey says the enforcement notice sent to gun sellers and manufacturers clarifies what constitutes a "copy" or "duplicate" weapon under the state's assault weapons ban, including copies of the Colt AR-15 and the Kalashnikov AK-47.Despite the law, Healey said an estimated 10,000 copycat assault weapons were sold in Massachusetts last year."If a gun's operating system is essentially the same as a banned weapon - or if the gun has component parts that are interchangeable with those of a banned weapon - it's a copy, it's a duplicate, and it's illegal," Healey said at a press conference in her office.Healey says the gun industry has openly defied the law and her office has a moral and legal responsibility to enforce it."I don't think she knows what she is talking about," Mike Mavery said, who told Newscenter 5 he wouldn't be in line if it weren't for Healey's announcement. "I think its arbitrary and capricious."Jim Wallace, executive director of the Gun Owners' Action League said the group is trying to decipher what the enforcement letter from Healey means."For nearly 18 years since the passage of the 1998 Gun Control Act firearm retailers, gun owners and state agencies have been operating under the same interpretation. Now, suddenly, without warning or any due process a single person with a clear political agenda decides to change the rules," Wallace said in a statement.The Massachusetts assault weapons ban mirrors the federal ban that expired in 2004. It bans the sale of specific and name-brand weapons and explicitly bans copies or duplicates of those weapons."This is not going to save any lives," Mathew Colson,a  gun collector, said. "This is but a political ploy just to prove a point, the point being she can do whatever she wants." Healey said gun manufacturers make what they call "state compliant" versions of banned weapons with minor tweaks to various parts of the weapon. She said copycat guns are sold, for example, without a flash suppressor or with a fixed instead of folding stock - changes that Healey said do not make the weapon less lethal. She said those weapons are still illegal.Healey said a weapon is considered to be a copy or duplicate if its internal operating system is essentially the same as those of a specifically-banned weapon or if the gun has key functional components that are interchangeable with those of a banned weapon.The notice sent out to gun dealers and manufacturers also says that assault weapons prohibited under state law can't be altered to make their sale or possession legal in Massachusetts..