The real reason for this thread... I purchased Hornady's modified .17 Remington case. I planned to slowly bump back the shoulder until I matched my chamber of my 17-222. Applying mild pressure, Imperial Wax, and small incremental bumps, I started moving the shoulder as planned. On the 3rd bump I must have gotten a little greedy...Stuck Case in my die! I attempted to extract the case with slow consistent downward pressure. The case head separated cleanly from the body along the extractor groove. The 5/16" threaded hole through the center of the case left this area too thin for any torque.
The standard Stuck Case Removal Kits offered by all the die manufacturers ($15) will not work because the kit comes with a much smaller screw & tap then the existing 5/16" hole in your modified case. You may want to consider buying the 5/16" x 36tpi die when you buy the tap. I tried everywhere to source a 5/16" x 36 tpi screw/bolt. I was told by the specialty fastener supply companies that this is a specialty item that must be custom made. I ordered the Die off Amazon ($10) and visited my friend (hobby machinist) to mill a bolt that would screw into the case stuck inside the die. I planned to use the steel cap that screws over the die from my Lyman Stuck Case Removal Kit.
Next Discovery - the cap is made from hardened steel that laughed at the HSS drill bit as we tried to open the hole to fit the 5/16" bolt. A Carbide Cutter, either drill bit or endmill cutter, is required to cut this metal. Unfortunately, he did not have a carbide bit that size. If you don't have one then let me warn you these are not cheap!!! I had some initial sticker price shock (Amazon) with carbide drill bits averaging $275 and carbide endmill cutters averaging $75 (shorter length means less carbide material = cheaper). I found a really cheap carbide endmill cutter for $25 that did the job.
It was a 17-222 forming die from a set (vintage 1971) that is no longer available so I made the extra effort. A machine shop probably would have charged me a few dollars less, but not a whole lot of difference.