no one needs a machine gun for hunting or self defence.
And yet the only organization in America that is legally allowed to kill American citizens has machine guns.
what you dont realise is the NRA sell to both the cops and citizens
they sell a handgun in the 1950's to cops. then advertise citizens need hand guns too in the 60's
they advertise because citizens have handguns. cops need shotguns in the 70's
they then advertise citizens need shotguns too in the 80s
they then advertise cops need rifles in the 90's
they then advertise citizens need rifles in 00's
they then advertise cops need fully automatics in 10's
they then advertise citizens need fully automatics in 20's
they then advertise cops need tanks
and so on and so on
yep next move is citizens need armour plated vehicles with projectile weaponry
...
but addressing just your point. yes in law if someone waves a gun around or warns you that they are armed. you then have the right to defend yourself because suddenly there is a potential risk to life.
that defence works both ways. and in of itself a reason why so many deaths occur.. just having a gun
the NRA tries to advertise that citizens should walk around with guns. knowing it will cause issues by suggesting such
if your going to open carry. expect some people to look at you in shock and have the police check you out
the NRA wont come save you when your stopped and questioned. all they care about is getting more gun sales. they will not pay your bail