Why buy a bump stock for converting a semi-automatic rifle into an “automatic” one when you can buy a full-automatic rifle on online forums for a mere $850?
With a small amount of Monero (XMR) you could probably make this happen.
Courtesy of U.S. gun control supporting tax payer arming of “moderate” rebels.
https://edition.cnn.com/2018/02/20/middleeast/us-weapons-telegram-syria-intl/index.html