Back in the late '80s or early 90's Remington made this load in standard .38 SPL. I never got my hands on any, but I did manufacture my own.

I used 000 swaged lead buckshot, lubed it and loaded it into .38 cases using the loading data from an old Speer #9 manual, for standard pressure 140 gr. usuing Unique powder (each 000 buck weighed 71 gr.).

Worked just fine and was fun to shoot. However, if I were to do it again I would use the slowest burning powder available so that it filled as much of the case as possible. The problem with Unique was that there was not enough powder to keep the balls from falling down into the case. I solved this by stuffing half of a cotton ball between the powder & projectiles. The balls fit a bit "spongy" into the case, but it worked just fine.

The loads shot great out to 10 or 15 yards, and were extremely pleasant. Not much contact with the bore for the round balls, so there's not much resistance meaning not much recoil. What was better was all of the cotton floating in the air and drifting out of the barrel after the balls went downrange.