Pod,
I used brass wire as it is easy to make them to size by wrapping a case and cutting the space for the extractor. I flatten the ring till the case will headspace then used epoxy to hold them in place. You need to be careful to to not glue the action shut.
Have used it for Mauser A base cases as well as using it for making 9.3X74 brass fit a 40-85 Ballard.
Cheers,
Laurie


falling block