Gunzo: I can give you a short answer, until the experts chime in.

In 1958, H.H. Harris ordered 500 .44 Magnums with 5 inch barrel length. Not exactly sure if all were delivered, as they were sent over a period of years. Sometime back, it was estimated that some 200 to 250 were documented to have surfaced. There have been a couple threads here of pre 29s ordered, made and shipped prior to the H.H. Harris order.
At one time there was a lengthy thread on the 5 inch .44 Magnums that was very informative. I have not been able to find it, as it is pretty old.
There have been some that have been cut to 5 inch after shipment. Gun writer Mike Venturino had one so converted. There was once a member here who had one that appeared original, but would not letter as having been shipped in 5 inch.
Smith made a model 544, Texas Wagon Train commemorative in .44-40 in five inch that looks just like the .44 Magnum. It might be easier to find while you are looking for .44 Magnum.
Good luck in your search.

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Richard Gillespie
FBINA 102