Here is a replacement shell for the Nerf Sledgefire Blaster.

This is a work in progress. I have not been able to get a consistent seal yet with my prints, even with the bottom lip. Derivatives would be welcome.

Update: I have added a v007 *.stl. This one consistently fires, but ranges are less than half of what the nerf shells it came with can get.

I have included some supports for the thin spines, but you will also need to print with support as there is a thin lip on the bottom.