Reminder that 2A was expressly drafted to prevent the federal government from disarming the states at a time when the founders, fresh from defeating a tyrant, were fearful that unarmed states would be prone to invasion by neighboring nations or an authoritarian federal government. That's why the "well regulated militia" language is there. 
The authority over who could own a weapon, what types of weapons, and for what purpose, was always intended to be left to each state to decide within its own borders.  
This notion is clear from the nation's laws up through the 20th century. When throughout US history jurisdictions banned certain firearms within their state and city limits, prescribed loyalty oaths as a prerequisite to possessing firearms, or banned the public carrying and display of firearms not connected with militia service, nobody argued that such laws were unconstitutional, because it was well understood and accepted that states had the authority under 2A to set their own firearms laws and regulations. 
The reason this all changed in the early part of the 21st century is not because constitutional scholars suddenly had an epiphany and realized that they had been wrongly interpreting 2A this whole time. 
It changed because the GOP, with the help of the Federalist Society, installed a wholly corrupt conservative supreme court majority that actively did the gun lobby's bidding by expanding 2A to include a right of firearm possession for individual self defense. 
By expanding 2A in contradiction to 200 years of precedent, the corrupt court made it nearly impossible to set firearm restrictions at the state level. This allowed the gun lobby to sell more guns in more states, and then pump those increased profits into the pockets of the GOP and the Federalist Society, which in turn used those funds to install more gun lobby-friendly politicians and judges. 
And around and around we've gone since the travesty of constitutional jurisprudence that was Heller. 
TL;DR: The GOP and FedSoc invented a right to possess firearms for individual self defense under 2A and this American hellscape we're trapped in today is a direct result of their craven pursuit of power and profit.