A player in our campaign asked me to write up shotgun rules after noticing that the ones he was using had an average DV higher than sniper rifles. The rules I made got complicated really fast, but I enjoy complicated so they stand.
Warning: strong language
Let me know if you use them and how they work. I'm really interested to know how AV stacks up in your games--why wear light combat armor when there's a risk of depressurization literally everywhere--but feel free to adjust the curves as you see fit. Also, I think I've caught most of the logical and grammatical errors, but if you spot any feel free to point them out. Additionally if one of your players finds a great way to break things, post it here. I've included my design methodology in the second half of the doc.
Mucho gracias to Posthuman for creating such a fantastic setting, and a big shoutout to XCOM and the Long War team for inspiration (and blatantly stolen ideas).