Gun Builder is a cool simulator in which you have to build specific firearms with many different parts. Every time you finish assembling a gun you will proceed to the shooting gallery, where you can test the weapon. Once you have tested it, a new weapon will be available for you to build. You can also build your own guns and test what would come out of an AK-47 grip, a 9mm frame and a 12 gauge barrel, for example. Set free your creativity and build the perfect, most powerful gun. Enjoy.