Nice video from Duelist1954's channel on  reloading for the .577 Snider.  He starts off making cartridges out of 24 gauge shot shells with round ball, which makes a dandy plinking load.  He moves on to brass cartridges, which is pretty pricey for the huge brass shells.  He gets his supplies from Graf and Sons.  If you really want to shoot it cheap, you can even use the primed brass bottom of a shotguns shell, and just muzzle load the old Snider.  Enjoyable video from a guy who likes shooting old guns, and he has many more.