>privately owned cannons
>privately owned warships
>hand grenades and grenade launchers were a thing
>multi-shot firearms, such as the Nock gun, volitional repeater, Girandoni Windbusche, etc. existed along with primitive revolvers
>the first machine guns, such as the Puckle gun, the Chambers gun, etc. were a thing and even used by the American navy
>founding fathers were all highly educated men, many were military leaders like Washington, many were inventors like Jefferson or Franklin, and all were aware that technology, particularly in regards to weaponry, wasn't going to stay static and unchanging for all of time
>OY VEY THE 2ND AMENDMENT IS ONLY FOR MUSKETS, THEY COULDN'T HAVE FORESEEN MODERN FIREARMS TECHNOLOGY!
The entire idea of the Second Amendment is that the general populace has firepower on par with the police or military in the event that the government attempts to impose tyrannical shit on them, or in the event a foreign military attempts to invade America (the founders envisioned only a small standing army, enough for an immediate defense, with volunteer militias composed of civilians armed and trained like the army being used to rapidly expand the army to repel invasion), which means their weaponry needs to be identical to what the police and military are using.
This means the founders would be perfectly ok with ordinary Americans owning assault rifles, belt-fed machine guns, hand grenades, rocket launchers, shoulder-fired surface-to-air missiles, mortars, howitzers, etc. because all of those could be used to defend the nation against their own tyrannical government or a foreign invader. Privately-owned tanks, PT boats, fighter jets, helicopter gunships? Also perfectly fine. The "recreational nukes" argument is Jewish bullshit meant to distract you; only a millionaire could afford to purchase a nuclear warhead and maintain it (nukes require regular maintenance to remain operational, due to radioactive decay among other things; part of why the Russian and US stockpiles consist of thousands of nukes is because 2/3 of them are undergoing maintenance at any given time, so you have to have enough to nuke the shit out of the enemy while most of them are unusable at any given time), a citizen cannot practically use a nuke to defend his country from a foreign invader (nuke the invading troops? You just nuked your own soil. Nuke the enemy country? You just invited nuclear retaliation, with no input from your country's leadership.), nor can a nuke be reasonably used to protect yourself against your own government because you would be nuking your own civilians and covering the landscape in fallout, not just blowing up government troops and politicians. Thus, anything bigger than a fighter jet, tank, howitzer, etc. is impractical for the average civilian and likely not covered by the 2nd Amendment.