We the people are the militia just as we are intended to be its regulators. In order to be a well regulated militia it need to have equitable arms. Not much a bb gun can do vs a semi-automatic rifle. Going up against those odds is poorly regulated.
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"Sir William Blackstone described this right as an auxiliary right, supporting the natural rights of self-defense and resistance to oppression, and the civic duty to act in concert in defense of the state.
While both James Monroe and John Adams supported the Constitution being ratified, its most influential framer was James Madison. In Federalist No 46, Madison wrote how a federal army could be kept in check by state militias, "a standing army ... would be opposed [by] a militia." He argued that state militias "would be able to repel the danger" of a federal army, "It may well be doubted, whether a militia thus circumstanced could ever be conquered by such a proportion of regular troops." He confidently contrasted the federal government of the United States to the European kingdoms, which he contemptuously described as "afraid to trust the people with arms." He assured his fellow citizens that they need never fear their government because "besides the advantage of being armed, which the Americans possess over the people of almost every other nation, the existence of subordinate governments, to which the people are attached, forms a barrier against the enterprises of ambition".
In Caetano vs Massachusetts (2016), the Supreme Court reiterated its earlier rulings that "the Second Amendment extends, prima facie, to all instruments that constitute bearable arms, even those that were not in existence at the time of the founding" and that its protection is not limited to "only those weapons useful in warfare".