Making split rings

I am working on a project where I want to use split rings in lieu of
jump rings. I am using copper and have not been able to locate what I
am looking for to buy. I would rather make them myself anyway.

I have searched the web and Orchid archives. I see they are heavily
used in fishing lures, but most of these are stainless steel or
anodized a copper color. That just isn’t going to work.

What I am wanting to make is split rings between 5mm and maybe 2cm
in diameter. I would like to make them a little more than just coiled
wire with partial overlap of the loop. What I am thinking is to coil
a length of wire around a mandrel and then make alternate cuts. This
is the point where I am trying to come up with an efficient way to
work. I would like to thin down the overlapped parts of the ring. Two
methods come to mind. 1) grinding/filing away about half the wire
thickness. 2) forging the overlapped parts to reduce thickness and
then file off the extra width.

Both seem pretty labor intensive for one or several or even a
hundred split rings. Method 2 is a problem because the flattening of
the pieces causes them to deflect so that the overlapped portions are
no longer overlapped. They are more of a semi split coiled ring.

Another idea I have not tried out is to make the rings as described
above and stack into a metal tube/pipe with I.D. matching O.D. of
coils and then use a metal rod that fits inside the tube/pipe and
compress the rings.

I am not necessarily expecting these rings to be perfect, but would
like to figure out some way to ensure a bit of consistency in form
and less labor per ring. Any ideas?

Ashley Webb