The government must then justify its regulation by demonstrating that it is consistent with the Nation's historical tradition of firearm regulation. Only then may a court conclude that the individual's conduct falls outside the Second Amendment's 'unqualified command.' (2022 Bruen Opinion of the Court)
My understanding is that the FCA and GCA are the primary laws that prevent unlicensed people from easily buying and wielding highly destructive weapons like machine guns, grenade/rocket launchers, bombs, artillery, vehicles with working guns, and possibly even nuclear devices (I'm not certain about the last 3 categories, those could be covered by other acts but those could also all be construed as Second Amendment limitations).
There is clearly no historical tradition of limiting Americans from owning machine guns, grenade launchers, tanks and military helicopters because they did not exist in the 19th century. (I'm not sure about artillery; cannons were definitely around at the time of America's founding and maybe some states had laws preventing people from blasting away their neighbors. On the other hand, a well-organized militia probably should have trained on artillery before the US started maintaining a large peacetime standing army.)
Thanks to Bruen, could these acts be knocked down as unconstitutional such that the next Las Vegas-style mass shooter could use one of these automatic 40mm grenade launchers? Alternately, when might we expect that insane precedent be overruled? Never with the current SCOTUS?