I would also like to respectfully disagree with the notion that this is not ".38/44" ammunition. A Western Rifle and Pistol Ammunition Handbook from 1935 lists their Super-X .38 Special Metal Piercing round, 150 grain Conical at 1,050 fps. I have one of the pre-war boxes and it specifically lists the Smith & Wesson .38-44 revolver. Winchester's load of the same period is rated at 170 fps higher than the Western load, a few years before they merged.
Ed