I'd hold onto it until summer, find a car with an obama/patrick/warren sticker and open windows, toss it in the back, make the "i just seen a car with a assault rifle in back, hurry, everyones about to die" call to the cops. Then sit back knowing I did my part to bring the government that these type of people voted for and so desperately want right to their doorstep to kick them in the face and execute their dog.
Bring it to a gun buyback, but make sure to record it. We need to see this. If they won't accept it, throw a fit about how you're calling Obama and telling on them about the killy stuff and babies, start singing. Make sure you wear an Obamabot t-shirt, we need to make them look like loons.