So I read it in an army or marine magazine a few years ago. But here's a link that lightly goes over it https://3dprintingindustry.com/news/mcsc-trains-us-marines-t...

Google marine 3d print, cool articles and stories.

Lookup marine plywood drone. They had to do it with a firm due to gov contracting laws. But from what I understand it's mostly designed/built by marines (word of mouth). There are more and more stories like this that are popping up. Sad part, big contractors cry foul of marines making repair parts and their own gear. From what I understand, that's why they need other firms to "take ownership" on projects.

Theres a cool 3d print barracks project you can Google too.