jeweler,
You can't use 38S&W. It is a few thousanths larger in diameter than the 38S&W Special and 357 S&W Mag. You need to shorten either 38spec. or 357mag(38spec is easier)cases.It is a common misconception that the 38S&W is a shortened 38Spec.,it is more like the 38 Colt case loaded with an inside lubricated bullet, to higher pressures.
Mike