The reason that there are very few revolvers with 9mm, .40, etc., is that you must use moon clips (I believe someone has some kind of one-off ejector star that allows the use of rimless cartridges in a revolver cylinder).
you'll find that a glock 27 and a J-frame carry about the same in the pocket
may find that...but I didn't, and I don't know anyone else who has. I read very, very few posts from people who pocket carry any type of Glock, while I have read many posters who say that the Glock (any Glock) is not a pocket pistol.
On the other hand, only about a bazillion people throw an S&W J-frame in their pockets every day (including at least three that I know personally) and that number is growing daily.