This is my first post. It's been tested and proven reliable in all Buzz Bee offerings (I finally got a Rapid Fire Tek and confirmed they cycle as well as the original!) They're meant to replace BuzzBee Toys shells and are designed to mimic the dimensions of the original. They also work better (shoot harder and more accurate), accept short darts, and seem to be a solid performing shell with my experimentation. I recommend at least 20-30% infill, 4-8mm wall thickness. You CAN get away with 15 or even 10% but it becomes weak. Expect them to degrade if left outside if you print in PLA. Print with a random Z-seam to eliminate the pronounced seam bump that can affect fitment in the chamber of one of Buzz Bee's offerings.

Doesn't need supports or any adhesion support, but a brim might help if you want it. As well, a little extra material around the head of the shell can prevent premature ejection, though I toleranced these quite carefully to prevent this as much as possible.