To be accurate, there are no weapons features that have been banned from private ownership and use in the U.S. at the federal level. Certain weapons fall under regulation of the National Firearms Act and require payment of a tax before transfer. Examples are machine guns, suppressors, destructive devices and short barreled rifles/shotguns. These are all legal to own by individuals at the federal level.
A few states do outlaw or ban some specific NFA weapons however - for instance 5 states outlaw individuals from possesing machine guns.
Drawing a line between civilian and military use suitability is difficult, but that doesn't mean there is no difference. That's why there is no assault rifle law in the US, but rather some features of weapons have been banned from private use.