Not all machine guns are assault rifles, but assault rifles are by definition select-fire machine guns (burst or full auto), firing an intermediate cartridge, and of rifle-like design.
True machine guns like the M2, M240, M249 aren't assault rifles, nor are machine pistols.
We do need a new term for "military-style semi-automatic intermediate caliber rifles", but assault rifle is already used.
I'd suggest "black rifle" or "military-style rifle".
Maybe "Civilian Class" "Law enforcement class" and "Military class" buckets. And require various licensure for each category? (Its going to piss a lot of people off though...)
2) Progressive licensing for possession (various classes of weapons); license the owner, not the gun. A gangster with a .25acp pistol is a lot more of a problem than my .338 Lapua Magnum rifle.
3) Streamlining all existing regulations, which is a combination of eliminating ineffective/irrational stuff (SBR/SBS being more regulated than pistols, 922(r) parts counts, etc.) and strengthening other parts (licensing, treating handguns and semi-auto mag-fed rifles more strictly, etc.) Deregulate suppressors, deal with SBS/SBR, and raise the full-auto tax to $2500-5000 indexed to inflation, but also allow post-1986 automatics under that restrictive regulation.
That's effectively what we have now. Civilian-class is any semiautomatic, bolt-action, or single-shot weapon. Law-enforcement-class adds fully automatic weapons. Military class adds grenade launchers, proper machine guns, antiaircraft guns, artillery, naval guns....
True machine guns like the M2, M240, M249 aren't assault rifles, nor are machine pistols.
We do need a new term for "military-style semi-automatic intermediate caliber rifles", but assault rifle is already used.
I'd suggest "black rifle" or "military-style rifle".