My homemade muzzleloader could use homemade ammo. I used homemade projectiles and the electrical ignition did not need primers. I bought the black powder, but it can be made without too much trouble.
I do not know where his came from. Probably smuggled factory ammo. But makeing homemade ammunition is not that difficult.
Admittedly, black powder is a safer propellant than chlorate based propellants (less brisance), but they are still very effective for expedient homemade ammunition.