Read the federalist papers: This tells us the truth about the constitution.
USC › Title 10 › Subtitle A › Part I › Chapter 13 › § 311
10 USC § 311 - Militia: composition and classes
We are the militia, you are the militia. The states can call up the militia but arguments that the militia is the national guard are false.
The wise people who wrote our constitution intended that the citizens be as well armed as soldiers, the same as Switzerland is today. That means full automatic weapons and any other weapons a person can physically carry.