I like what you did there. I never considered making my own stuck case removal tool...very creative. In the one case that I got stuck in die, I removed the decapping assembly and drove it out from the top with a brass rod...same one I'd use to clear a squib load. Sadly...my case was a precious .458 Socom that I HAD lubed...but perhaps I didn't lube it enough.
Sorry, can't take credit for that idea. My buddy google helped me out. I have used sockets in a similar manner while pressing out bushings for car repairs though.
This case got its neck all buggered up when something inside the seating die got stuck in a funny way. I wanted to save the case if I could, but since it already had a primer installed I didn't want to get sizing wax all over the case (since I couldn't wash it off properly due to the primer being present). Should have just removed the primer and used wax anyway, but was trying to avoid removing the live primer if I could get away with it...
Anyway, I did smear a little bit of One-shot on the case, and figured I'd be OK. I left the capping stem and expander ball in so it would size the neck properly, but removed the decapping pin so the primer wouldn't get pushed out. It worked the first time and the case was a bit better, but I figured I'd try once more.... and got it stuck
Yup, you read that right - got the case stuck with a live primer installed, and no decapping pin in the die.
So I removed the die, pulled the seating stem up to jam the expander ball against the case neck, and un-threaded the decapping stem. Dropped the decapping pin down into the expander ball, then threaded the decapping stem back in (that procedure took a few tries to pull off...). I put the die back into the press but left the ram down, and used an "F-style" wood clamp between the frame of the press and the top of the decapping rod to slowly and carefully press the live primer out (all while wearing safety glasses and ear muffs). Then I repeated the first half of that procedure to remove the decapping stem and pin, leaving just the expander ball in the case, and went hunting for taps, lol.