The Congress shall have Power To lay and collect Taxes, Duties, Imposts and Excises, to pay the Debts and provide for the common Defense and general Welfare of the United States; but all Duties, Imposts and Excises shall be uniform throughout the United States;
To declare War, grant Letters of Marque and Reprisal, and make Rules concerning Captures on Land and Water;
So what is a Letter of Marque and Reprisal? Essentially, it was a government license to attack, capture, and sell enemy ships. The letter of marque is what distinguished a privateer from a pirate. In order to do that, you need an armed ship yourself. Letters of marque weren't issued to US Navy ships, they were issued to the private owners ships who would outfit them for privateering, including naval artillery.
In the 18th and 19th Centuries, an armed warship was the closest thing extant to a weapon of mass destruction. And we haven't discussed the private ownership of artillery on land or inland waterways, which was common through the 19th Century. E.g., flat boat-mounted swivel guns used by fur traders in the West.
So can we agree that the Second Amendment does protect the right to own military weaponry, just as the First Amendment protects your right to spout uninformed bullshit on the Internet?