I used a 9/16 socket, tape down trigger so it rotates about once per second.
Set case into socket. Adjust torch until bright blue flame is about an inch long [fairly low setting], i then aim torch slightly downward angle right at the shoulder. Bright blue flame just about touching case. This leaves the case mouth above the flame. I do this is a dark room with door shut. Case changes color about 6-8 seconds. I watch the case mouth, see a faint glow and stop. I wear a welding glove on left hand for removing each case.
View attachment 246271
View attachment 246272