After receiving some feedback from my bin inserts I decided to come up with this. It holds 9 AR style magazines in the 48-22-8435 box and the insert just drops right in. I printed this in two halves since my printer wasn't large enough to print the entire thing. I would recommend to either glue or melt the two halves together with a soldering iron. Since it is slides in so smoothly the two halves won't stay together if the box is turned upside down as well as the whole insert if no magazines are installed. If they are installed they will not fall out though as there is only a slight gap between the closed lid and the back of the magazine once the lid is locked.

Please note that the licensing doesn't allow for my file or prints of the file to be sold