Re: "restrict it to a musket"
"This often repeated suggestion ignores the fact that the American colonists and their immediate successors generally had the most modern and effective of the available that they could afford. For personal weapons, they had the same range and types as those in any military service of the time."
And a lot of constitutional experts think that that equivalence between military and civilian armament was the intent of the writers of the second amendment.
Remember that democracy and civil rights (the Magna Carta) did not really gain traction (post Athenian Greece) until the longbow gave the populace weaponry effective against the ruling class whose armour previously allowed them to impose whatever rule they wanted with impunity. The full story is more complicated, as always, but that's the bottom line.
Biting the hand that feeds IT
