It's easy really... smuggle a little bit in every day and build it!
When I was in the US Army I got stuck working in PLL (Parts and stuff) to try and help them out.
Bottom line. After about a month there I figured out they still had EVERY part for M-14A1's available for order.
I passed....rumor control says many other's didn't.
Look for me on Twitter, Instagram, Facebook or Tic Toc...or anywhere you may frequent, besides SimHq, on the Global Scam Net. Aka, the internet. I am not there, never have been or ever will be, but the fruitless search may be more gratifying then the "content" you might otherwise be exposed to.
"There's a sucker born every minute." Phineas Taylor Barnum