*UPDATE 2: REMODELED IN AUTODESK FUSION - Updated to be individual parts/user serviceable. There is a (STD) model that is just the normal full sized straight petals, and a (LITE) model that has straight, but narrowed petals. Removed bottom rubber band notches from petals. Core is two pcs that can be assembled using 5x M4-0.7x16mm SS button head socket cap screws (2.5mm wrench). Petals need 5x 6mm diameter x 12mm long SS dowels pressed into hole for hinge. May work on twist/spinning versions, whistle slot versions, or a couple others (golf ball launcher sized!!!???) in the near future. These should be able to be printed without any supports. Recommend printing in the toughest material you can. Will be printing and testing these using .22 ramset blanks levels 2-5, .556 blanks, and .308 blanks.

*UPDATE 1: TWIST v2 SUPPORT GAP ADJUSTED TO .3mm

Having had success with my can cannon pellets, I wanted to up the ante a bit. I got the idea for these from an anime called Trigun. One of the characters totes what appears to be a minigun but it fired stun batons; long cylinders of unknown material that open from the front into a rather large "+" shape as they went down range to strike an opponent. I opted to have my design deploy 5 "petals" rather than 4 for balance and bore fitment. The first is a simple fold open type assisted by a rubber band wrapped around the tabs at the base. The second version has the petals shaped so that, with any luck, airflow over them would help induce a spin to the round increasing accuracy and stability in flight. Both versions have support material included in the part/stl files and it performs quite well, but YMMV. I can upload non support versions upon request. I have not test fires these yet so I have no idea if they will work. Hoping to get better weather soon so I can launch them and get it on video.