An assault weapon is not a firearms technical term. It’s a military term. It’s meaning has since been altered by gun control advocates. An assault weapon is the primary weapon used by a military armed force. WW II: the M1 was the main assault weapon. In Vietnam it was the M16. If I were to organize my own army, I wouldn’t have a sufficient budget to issue any sort of firearm. In that case the assault weapon would probably be a 36”-long 2 x 4.
Hence my comment re my .22 rifle.