Attorney Gen. Maura Healey on Wednesday put gun shops and would-be owners on notice that she is halting the sales of many types of “Massachusetts-compliant” semi-auto rifles.

Healey announced that her office was ratcheting up enforcement of the state’s assault weapon ban by targeting guns whose actions are similar to AR-15s and AK-47s but meet current cosmetic requirements such as being sold without features such as a flash suppressor, bayonet lug or telescoping stock. She contends as many as 10,000 such rifles were sold in the Commonwealth in 2015.

“That will end now,” wrote Healy in an announcement phrased as an editorial in the Boston Globe. “On Wednesday, we are sending a directive to all gun manufacturers and dealers that makes clear that the sale of these copycat assault weapons is illegal in Massachusetts. With this directive, we will ensure we get the full protection intended when lawmakers enacted our assault weapons ban, not the watered-down version of those protections offered by gun manufacturers.”

In a four-page guidance, the AG notes that any gun with an action similar to that of the Avtomat Kalashnikov (AK), UZI, Galil, Beretta AR70, AR-15, Fabrique National FN/FAL, FN/LAR and FNC; SWD M-10, M-11, M-11/9 and M-12; Steyr AUG; TEC-9 or revolving cylinder shotguns, such as the Street Sweeper and Striker 12, can no longer be sold after July 20.

Regardless of whether the gun has been altered to comply with the state’s mandates on assault weapons by pinning the stock in a fixed position; removing the pistol grip, bayonet mount or flash suppressor; or preventing the gun from accepting a detachable magazine, a similarity test in which the action is compared with banned guns will be the determining factor on if it is a “copycat design.”

Likewise, if two or more components of the action, such as the trigger assembly, bolt carrier group, charging handle, extractor or magazine interchange with a banned design, it will likewise be considered an assault weapon and banned from sale.

Those in possession of such clones as of July 20 will be able to keep them as long as they have written evidence they were transferred on or before that date. She encourages anyone with such a gun wanting to dispose of it turn it into the state police or take advantage of a buy-back program.

Healy says she anticipates legal challenges to the new mandate.

“In the dozen years since the federal assault weapons ban lapsed, only seven states have instituted their own assault weapons ban,” she wrote. “Many of those bans have been challenged (unsuccessfully) by the gun industry, and we anticipate our directive may be too. But our job is to enforce state laws and to keep people safe. This directive does both.”

Data from the Federal Bureau of Investigation for 2014, the most recent available, shows that of the 131 homicides in Massachusetts recorded that year, none were attributed to rifles of any kind, while no less than 34 were chalked up to knives and three to bare hands.