I've made an updated version with even more improvements - check out the link below
https://youtu.be/GE1QYgi05qU
This is my 2nd version of my shotgun shell lighter. I've made a bunch of improvements since I made the first one including much better sealing, reinforced shell and a whole bunch of other additions.
This version is also a lot easier to make!
I've also published a step by step guide which can be found below. It includes links to all the parts needed to make your own
Here's a link to a step by step guide on how to make one plus parts needed
https://www.instructables.com/Shotgun-Shell-Lighter-V2/
Here's a link to the original build
https://www.youtube.com/watch?v=Ht7_1DvRgFQ&t=4s