This is my version of the MasterKey, which I was inspired to make after watching an episode of Sons of Guns. To those who don't already know, the MasterKey is a shotgun mounted on the bottom rail of an M16 assault rifle. It's basically a double purpose weapon; the shotgun is used to breech doors and the M16 against the bad guys on the other side.Obviously, you don't need to breech doors in an airsoft war, nor does this shotgun have the potential. However, it does work for having your main/secondary weapon at easy reach; the M16 for long range and the shotgun for close range. This prototype it held up by rubber bands, which obviously isn't permanents, but it is flimsy. Therefore I'm trying to come up with a way to be able to attach the shotgun, but also be able to take if off when I don't want it. My idea is to attach it with zip ties, but if anyone has any other ideas, comment below.