It's a little known fact in these modern times that as you pointed out for a long time there was a political theory that States could violate your rights under the 1st 10 amendments but the federal government could not.
That political theory finally went away.
But at the time there was very little distinction between what was a military style weapon and what was a civilian weapon.
Now however there are vast differences in a lot of military weapons fire power and ballistic killing capability versus civilian weapon