Here you’re moving into machining and away from jewelry making.
Couple of things: stainless steel work hardens very quickly. This makes it more difficult to cut, saw, drill, etc. It will even work harden while you’re drilling if the bit is a little dull. Annealing the coil before cutting the rings apart should lengthen the life of your saw blades. Annealing stainless without a temperature controlled kiln may be difficult, however.
This is the sort of work you really should job out to a machinist shop, who have the kind of equipment needed.
Here’s a video of Mr.Pete, “Your Internet shop teacher,” wrapping steel rings two ways: around a mandrel held in a vise and on the lathe.
