A replacement shell to launch mega darts from a nerf sledgefire. Requires modification on the barrel to reshape a bit of the wall that holds the shell in place. This won't prevent you from shooting normal shells, but without this the megadart won't fit down the barrel.
The photo's and the video show me shooting a MK1. There have been some small changes and it should work better now.
The printed material is a bit rough, even when set to polished, so I suggest sanding the outside surfaces with some fine sandpaper.