2nd Amendment anyone?

Famously, the M-16 battle rifle is a development of the AR-15 semi-automatic rifle. The fully automatic/semi-automatic difference seems to be the dividing distinction between military rifle and civilian rifle. At the link below a fully automatic turret-style heavy machine gun system is (deliberately) generically described, along with a brief history of its development.

Question: since Gatling type guns are covered by the 2nd amendment as not requiring a special license for a citizen to own, how soon can we expect a privately developed civilian version of the weapon system described in the linked article? Bonus question: what relevance does such a development have regarding civil unrest, or even military invasion, here in the US?

https://strategypage.com/htmw/htweap/articles/20200607.aspx