I've nearly finished the Magnum gun now, and the price comes out to ~$40 for all the internal components to build 10 guns. The sound is usable (but very low quality), and the physical design is essentially complete. The code still needs some more work, but it's able to test all the hardware, which is what I need right now. I have one fully assembled gun, and I'll have more that I can complete as soon as I get the right switches and some better 3D-printed gun casings. My current 3D printer prints PLA fine, but needs a lot of help to print PETG reasonably well. PLA isn't heat-resistant enough to survive in a hot car, so I don't want to use that, but PETG should handle it fine. Anyway, I've ordered a Creality CR-10 3D printer, which should be able to print PETG very nicely, so I'm waiting for that.

The first Mother Beacon PCB design is complete and ready to be ordered and tested. I'll probably be ordering it today, along with enough components to finish my 4 partially-complete guns and to build 10 more guns after that.

I still haven't solved the vest problem, but I've ordered some vests to see whether I can find one that will work. Once I get a good vest, I'll attach sensors to it, verify that the setup works, then order more vests and more sensor PCBs and components.

Overall, I'm pleased with the progress I've made, and I'm looking forward to finishing this project.