Nor is it an assault rifle.
So please print and tv media, get it right.
A machine gun fires an unlimited number of rounds as long as the trigger is held. Machine guns have been illegal in the US since 1932 for private possession and use.
The correct legal definition of an assault rifle is one which offers switchable choice between single fire, burst (usually three) fire and auto fire. No weapon availailable for commercial sale in the US offers more than a single fire option. A semi-automatic weapon, handgun or rifle, rechambers the next round after the last round was fired. To fire it again, the user must pull the trigger again.
I purchased my semi-auto AK over the Internet from a seller out of the state of Missouri. The firearm was sent by freight after the purchase to a local federally licensed firearms dealer who, before the rifle was transferred to me, ran me through the national NICS check.
I passed the NICS check, as I have for every other weapon I've purchased (I also passed the deeper FBI investigation to qualify for the STL County Concealed Carry License).
Yup, kids, it's really true: only outlaws have illegal weapons.