I have three SledgeFires. The first two I cut up and modded, and the third i found in the thrift store with TWO ORIGINAL SHELLS. I want to keep this one stock…

But that empty slot in the stock shell storage made me anxious. 

I tried the printed 3D shells, but the ones I had only worked with a totally flat breech, not the weird little raised lip that pressed into the original rubber seal.

So I decided to make my own. 

It comes in two parts. the first part that holds the darts. It even allows the little things that check to make sure a barrel has a dart in it to function.

The second part is the thin seal. It glues to the bottom and works rather well.

My MAIN goal was to make the shell as much like the original shells. SO, I made the barrel rather big (13.6mm) and made a 12.7 mm “collar” at the bottom of the shell barrel to capture the dart. 

I did this to not only make the shell fire any diameter dart (whether brand new and firm or old ad squishy), but to allow the smart AR to work. 

PRINT SUGGESTION: I suggest one wall with 100% infill. It is a very sparse fill, and found that it takes as long whether it is 100% or 10%. But the 100% prevents any weird “artifacts” (like holes or gaps). No brim needed, but you will need supports; they are very tiny and cute, though. No issue.

I will add a shell i created with uniform 13mm barrels that may work with more powerful springs or with really loose fitting darts.

And yes, the shell does snap into the barrel and pop out when you fold down and cock the blaster. And it does fit into the stock shell holders. After i added the ribs, it fits perfectly with minimal wiggle.

I think this final version is the one I wanted that works BEST with a stock SledgeFire. 

I have also included a shell that works with flat seals. Do NOT use the 2mm brim on this one; it is long enough to press and get a good seal on a modified flat seal.

EDIT: If the shell gets stuck in the breech, just sand the sides of the collar (where you glue the brim to) and make it even with the brim. Not too much; sand, then check. it will eventually eject like a dream.

EDIT 2: I added ribs. Cuz… perfectionism.