This is one of the ways in which the USA is more like 50 little countries than a single one. At the federal level most everything besides post 1986 machine guns, including 120mm cannons and explosive shells along with a tank to move them around, can be had with some paperwork and a tax stamp, which is $200 or less.
There are businesses in Nevada[1] that will let you drive tanks and fire off howitzers[1] that are privately owned.
However many states, and in some states counties and cities, have additional restrictions on what they permit. For example, a muzzle loading revolver isn't even considered to be a firearm federally, but in NY State if you happen to have powder and lead handy congratulations you're now a felon even in your own home unless you have a handgun permit.
The barrel of the revolver is effectively 6 terribly short smooth bore muskets. Be sure to load them before the shooting starts. Then you can fire six shots in rapid succession, before changing to your other revolver. You did remember to buy two?
You load all six chambers, or five if it’s an antique without a firing pin safety. Typically this is accomplished by pouring the powder charge into the front of the cylinder and then placing a lead ball on top of it and ramming it into place, although one can also remove the cylinder altogether with some models and load it externally.
The end result is you can get 5-6 shots off quickly, but reloading will take rather a lot longer than with a cartridge firearm. This is one reason people carried two revolvers in the old West. Needless to say they’re of little interest to criminals, but fairly popular amongst sportsmen and re-enactors and such.
Not always. One of the biggest advantages of a revolver is that if you have a misfire you still have your next chamber waiting for you. That doesn't go away.
There are businesses in Nevada[1] that will let you drive tanks and fire off howitzers[1] that are privately owned. However many states, and in some states counties and cities, have additional restrictions on what they permit. For example, a muzzle loading revolver isn't even considered to be a firearm federally, but in NY State if you happen to have powder and lead handy congratulations you're now a felon even in your own home unless you have a handgun permit.
[1] https://www.battlefieldvegas.com/