10% infill 3 walls 0.25 layers 0.4 nozzle but 0.6 works to. I used ESUN pla+ but regular pla will work. Here is the filament I used
https://www.amazon.com/eSUN-Filament-Dimensional-Accuracy-Printing/dp/B07FQDKR28/ref=sr_1_1_sspa.
You can either print the spring or buy it here.
https://outofdarts.com/products/extra-long-short-dart-mag-dart-spring-for-3rd-party-3d-printed-mags?_pos=1&_sid=7b8bd5ec7&_ss=r
or you can bend an old nerf dart mag spring with this model
https://www.printables.com/model/562308-nerf-full-to-half-dart-mag-spring-bend-guide/files. I have not tried the printed spring you may need to extend it or stretch it out. If you do print it use pla+.
The author remixed this model.
Added curve to make it a banana mag