Aerod1, as to how it works, most broken case extractors are expanding mandrels and work on cases with case head separation. “I have a shell to remove that has no case head” and that sounds like what you have, as with everything else, one model does not fit all.
Taps come in sets of three, bottom, starter and tapered, I have removed 30/06 cases with case head insipient separation with a 3/8 course tap, I have removed cases that do not have a case head with a slide hammer, I have removed cases with a slide hammer that were fired with over pressure loads, meaning the case head was attached but had a primer pocket/flash hole that were .050 thousands larger in diameter than than a large rifle primer.
“Can someone tell me how a broken shell extractor is supposed to work? This is a Numerich Gun Parts Corp. product number 881620. I have a shell to remove that has no case head”
I have a pile of pullers that have nothing to do with pulling cases, the pullers that work the best are the ones that do not rotate the part/piece being pulled. It would help to know what case you are attempting to pull.
F. Guffey