A Google search shows the NSN for that round was assigned 25 AUG 1979, and other references to "Naval Investigative Service Use Only."
1305-01-082-1233 - CALIBER .38 SPECIAL CARTRIDGE | WBParts
Never heard of it, but I got out in 1975. Just 'ol FMJ for us Sky Cops back then, unless you sneaked your own into the Bucheimer dump boxes.