So in August, the City of Fresno and Crimestoppers is having a "buy your gun day", where they will give you up to $200 for your weapon. They don't seem to care where ya got it:
Here's an idea: Maybe go to one of these places and buy the cheapest gun there (Can you find a gun for under $200? We have no idea.) and make a little extra cash by having the city buy it from you.
Or just yank the one in your grandpa's closet. You know he'll never miss it and you'll have a couple hundred bucks to take him to Hometown Buffet with.