Had one come apart in one of my other rifles a while ago(bumped the shoulder too far back on case that had been used 1 too many times over 15 or so years) and what I used to get it out was one of my wife's old painters brushes. It has a tapered handle on it so I pushed it in from the breech side as far as I could then gave it a turnso the wood could grab real good then tapped the whole thing out with a cleaning rod. The case was actually stuck by the shoulder with a fair amount of force that kind of surprised me with how well it worked. Not that I'm hoping to have to do it ever again but it's nice to know that they do come out without using taps and screwdrivers and other hard metalic tools. Can post a pic of it if anyone wants
I recently had a 300 win mag case head let go on me when load testing,
the case had 8 reloads through it at the time.
I used a tight fitting bore brush and push it half way into the case neck to extract it from the chamber.