Lanard Shellshock x-6 Improved Shells

### Why another shellshock shell design?

Original design by ExoticVoid comes out a little thin on the outer diameter, and too tall on the height of the divot, both were causing feeding issues bad enough to forcibly eject the magazine in my shellshock.

### a little backstory / explanation of files

I had previously spent a few days designing a shell for it, before realizing there was this design available, and that original design shared part of EV's flaws.

I've refined my design using EV's as inspiration, and have made a fully functional shell for half length/short/stefan darts and original lanard darts, and an experimental shell that technically can fit full length darts and will fit in the magazine.

And once again I have refined that design to fix a few minor geometry problems, and now accommodate up to shorter full length darts, such as the buzz bee long distance darts. Nerf Elite and Wafflehead darts do not work, and I am now convinced that without modifying the mag