So 38-44 data would be acceptable for this gun ?
I'm not familiar with 38-44 data, but I am with 38 +P+
. I have a Service Six chambered in 38 special and can tell you it is the same gun minus the chamber depth. I can swap cylinders with its 357 counter part and vice-verse.
I've been reloading for 20 years so I would recommend most to follow the instruction manual.