Assault rifle.

The SOAR (Special Operations Assault Rifle).

There are several different assault rifles - both by the true definition of an assault rifle and by the political motivated BATFE definition of a so-called "civilian assault rifle", manufactured by several different outfits. Which assault rifle did you have in mind, specifically?

The first true assault rifle debuted in 1942.

You will need to define assault rifle, and where you live. A TRUE assault rifle is a machine gun, and transfers of them are tightly regulated by the Federal government. What most people CALL an assault rifle is nothing but a semi-automatic rifle, and in most of the US, does not require a license to possess.