bknight:
Just a little input. My wifes Old Model Single Six Convertable (serial 815,xxx, with no prefix) is stamped 22 cal. Neither it's 22 LR nor it's 22 Mag cylinder has any markings and they are both fluted. The barrel slugged @ .2243, with sharp riflings. While this darling does shoot to different POI when switching from LR to Mag, it groups about the same at 25 yards. Even with the over sized bore (22 short/long/long rifle is usually sized to .223) I think the soft lead in the smaller calibers upsets enough to do a pretty good job of sealing.
I'm glad I saw this thread. Even though we've been shooting it for almost 30 years, until today, I had not noticed that neither cylinder had any markings. Since we handload a lot of 38 Special, we have not used the Mag cylinder much. Thank you.
Wally