These cartridges were loaded with a reduced powder charge for compatibility with old-time revolvers. The bullet is the regular soft flat point of 10,25 grams (158 grains) but the powder charge was reduced as to obtain a muzzle velocity of 250 m/s instead of the regular 300 m/s. The cartridge is identified by having half of the exposed lead portion of the bullet painted white.
The typewritten pasted label means “reduced charge”. The box is printed “.38 Largo Semiblindado”, which means “.38 Long Semijacketed”. In Spain it was common to call the .38 Special “.38 Long”, as opposed to the .38 Smith & Wesson (.38 Short).