From WCVB:

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.