One added issue is that S&W M-27/28 cylinders are too short for Keith's longer SWC bullet, I think the one that lists at a nominal weight of 168 grains. May be the 173 grain one. The M-19/66 has a longer cylinder. I don't think anyone has discussed Ruger cylinders in that regard. I don't use that bullet, so can't say.

If this is a factor for anyone, it has to be considered. That bullet will work in a .38-44 load, which is what Elmer Keith developed it for. The .38 case is shorter, of course.