ARE YOU SAYING, you overheated this brass with some sort of cleaning system and it annealed the cartridge brass ??
Brass annealed or not, it should not have been that difficult to extract the cases from the cylinder. First and foremost, check your reloads. If you have any unfired rounds from that hand loading session, pull the bullets and re-weigh your powder charge.
Sounds like pressure to me also. You stated "minimal powder", what powder and load were you using? With a lot of powders it's not safe to go below the minimum recommended....Thought I'd try these reloads 110gr.with minimal powder, and I wouldn't have to go back and tighten the screws. ...
I know that you said that you cleaned the cylinders after shooting .38 specials but is it possible that there is still a ring of powder residue left after shooting the .38s? It can be hard to get out and it is possible that the sized/resized .357 brass chambered over the residue ring but after firing was held in the chamber by the ring, after the brass expanded from firing. Just a thought... Since you said that you shot those same loads in other handguns ok.I had been shooting 38sp.for a while due to the fact the range I was using wouldn't allow mags, and try to preserve the gun's integrity....I want to practice with more than 38sp.I haven't used the SAA lately with 357....