When I began my USN career, a career that would continue for 30+ years, I took an oath to support and defend the US Constitution. Within a few years, I enrolled in a top tier university's Constitutional Law course, which opened my eyes to the fact that what is written in the Constitution has been interpreted and reinterpreted variously over the years by courts, with the Federal Courts and Supreme Court making finer and finer interpretations over time.
Not too remarkably, with fellow patriots in service from all over the US and its territories and even from other parts of the globe, even military members have differing opinions on what the Constitution means. One of the perpetual debates is over the 2nd Amendment.
Massachusetts's Lexington & Concord National Historic Sites are a stark lesson on what, "A well regulated Militia, being necessary to the security of a free State, ... " meant to our Constitution's authors and their fellow citizens. Had machine guns been part of colonies's militia arsenals, the only citizens who would be allowed to touch such a weapon would be a member of their colony's (later, state's) official militia, and only in compliance with orders and regulations.
Personally, I would like to have a small stock off hunting and defensive weapons safely locked up in my domicile, primarily to retain my marksmanship skills. But I know with 100% certainty that not everyone is capable of safely possessing ANY deadly weapon, let alone combat weapons or, God forbid, machine guns! I also think that in civil society, when the nation is not under attack by a hostile military opponent, the idea of "open carry" by droves of random, unregulated, gun-crazy civilians is very disturbing.
Unfortunately, over many decades various iterations of the SCOTUS has all but invalidated the "well regulated Militia" part of the Constitution, and a crazy sympathy has evolved with radical "shall not be infringed" advocates. God help America if we follow trend down the rabbit hole to calamity.