My friend has this gun he got at a garage sale, says 32 gauge special. cant find any ammo for it?

its in really good condition, looks pretty old. its single shot. ive heard about H&R's that shoot tranqu darts, but it just doesnt look like it would do that, and it doesnt say H&R. so... im not sure about it, but it does say palmer chemical equipment and powder projector, so i dono. i just want some ammo for it caise it looks cool