Your ammunition box is post-WWII, and was designed for law enforcement use to penetrate automobile bodies. The bullets are not lead, but rather some type of hard Zinc alloy. They were also made in .45 caliber.

The normal factory velocity given for .38-44 ammunition having a 158 grain bullet (which is nothing more than a hot .38 Special load) is 1125-1175 ft/sec, depending upon barrel length. I've fired exactly the same ammunition you have in a S&W K-frame revolver with no problems.

The last box of those I bought was about three years ago, and I paid the princely sum of $10 for a full box.