Gov. Deval Patrick is again appealing to Massachusetts lawmakers to approve his sweeping gun control bill.

Patrick is planning to testify before a hearing of the Public Safety Committee at the Statehouse. The committee has been holding hearings on nearly 60 gun-related bills across the state this summer.

Patrick's legislation would tighten access to high-powered rounds of ammunition, create four new types of firearms-related crimes and mandate that buyers undergo background checks before purchasing weapons at gun shows.

Critics say the bill goes too far and would punish law-abiding gun owners, and gun rights advocates plan to speak out.