Vall,
Can you see the liner? Do you know for sure it is lined? I ask this because 38-55 original length cases were often used for 9.3x57R/360 BPE.They were 1/8" short,but worked fine by seating the bullet "out". My thought was if a previous owner used 38-55 cases and some stayed with the rifle, a later owner may have just assumed it had been changed.Of course, as I often am, I could be wrong.
Mike