From the assault “weapon” page:
… is a political term
Meaning it was created by politicians. Do you consider a rifle a weapon? If so, then the definition for assault rifle IS the actual definition for assault weapon.
I believe it’s legal in NY, but most frown upon it because it may not be an ethical kill as .223 is considered a varmint round. It’s fine to hunt coyotes, rabbit, and predators though.