I did, my bad! I swear I’ve been on the Internet before!

The most likely scenario is a combination of heavier weapons from the EU & UK plus the same printed weapons Myanmar rebels are using. There’s a great episode of It Could Happen Here that covers how much 3D printers are being used there.

https://www.iheart.com/podcast/105-it-could-happen-here-30717896/episode/how-to-build-a-revolution-myanmar-104249884/