By the way my gun is legal as are all my neighbors. Outside of cities like Brookline and Cambridge law abiding citizens can easily obtain a gun permit.
Most towns in eastern Massachusetts will issue you a permit for "Target Practice Only". This means you need to carry your handgun in a locked case from your home to the gun range and back. You may be able to use the handgun for self defense within your house but it is likely you would be prosecuted for doing so.