A quick point:
While the difference between the .44 special and magnum in most cases is as described above, in the case of the M624 & M629 the frames are exactly the same per S&W.
I wanted a 5” barrel for my 624, I called S&W, no they said, not available, but you could change out the cylinder to the slightly longer mag cyl. and use a 5” Mag barrel which is available.
Evidently the 624s were just 629s with a different cyl & barrel, marked differently of course.
I am not advising the loading of .44 spl cases to .44 magnun levels.

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