.38 Special mid-range is normally a 148 gr. full wadcutter bullet loaded to target velocity.
.38 special High Speed sounds like an older company designation for a little hotter than standard load before the day of the +P designations.
.38-40 is an old black powder cartridge. Not a true .38, it is closer to a .40 Caliber bullet, usually 180 to 200 grs. loaded behind 40 grains of BP. It can be had through speciality outfits loaded with modern smokeless powder.