I like it, it is to the point. if you want a trigger, use the white-ish wall that allows electricity, connect a trigger to one side and a small peice of metal to the other (in the barrel). then put c-4 on that small peice of metal. when you spark the trigger, it travels through the wall, onto the metal and BOOM! the c-4 goes off and the gun does too!.
First creation, so don't be harsh!