That's an early .38-44 box, probably mid-1930s (pre-1938), often called the Remington "Dogbone" style. Given the lot number on the box, it is possible to date them fairly closely. I have seen both "Super Speed" and "Super-X" .38 Special headstamps, and I remember seeing a "REM-UMC .38-44 SPL" headstamp. I think there are also "PETERS 38 SPL HV" and "REM-UMC 38 SPL HS." I probably have examples of all those headstamps in my collection but I have not looked. I think any .38-44 headstamp from any manufacturer will use some means of distinguishing it from standard .38 Special.