The photograph on the left is of the slide ejection port and here we can see the stamps on the outside of the barrel. At the top is 7.65 M/M and then underneath that is the flaming bomb with the letter P inside. This set of marks tell us that the pistol is chambered for the 7.65 mm Browning cartridge which is also known as .32 ACP(Automatic Colt Pistol). The flaming bomb proof mark indicates that the pistol has passed test firing with a round that was 30% more powerful then normal.
The picture on the right is of the inscriptions that are located on the top rear of the slide. On the right side of the slide top it is stamped "Unceta y Compania S.A." and then on the left side of the slide top it is stamped "Guernica Espana".
The first stamp Unceta y Compania S.A. indicates Unceta(the manufacturer) and company Incorporated. The abbreviation "S.A." is basically the Spanish equivalent of "inc." or incorporated. It further can be explained with the Spanish words, Sociedad Anónima or Sociedad por Acciones.
The stamp "Guernica Espana" indicates the location of the Unceta y Compania S.A. The town Guernica is located in the Basque region of north-central Spain northeast of Bilbao. Its April 1937 bombing by 28 planes from the German Condor Legion during the Spanish Civil War inspired one of Picasso's most famous paintings, called Guernica. The Spanish rulers at the time commissioned Pablo Picasso to create a large mural for the Spanish display at the Exposition Internationale des Arts et Techniques dans la Vie Moderne Paris International Exposition in the 1937 World's Fair in Paris. The painting Guernica shows the tragedies of war as well as the suffering that war inflicts upon individuals, and in particular, the innocent civilians. This bombing and strafing of Guernica destroyed three-quarters of the city but spared the Astra factory.
How to field strip the Astra 300.
1. The first thing is to remove the magazine and make sure that there is not a round in the chamber.
2. The next step is to depress the barrel bushing that is located at the muzzle. This can be accomplished by using the floorplate of the magazine.
3. Turn the barrel bushing a 1/4 of a turn while applying rearward pressure as the bushing is under the recoil spring tension.
4. Now carefully ease the barrel bushing and lock off of the slide, and remove the recoil spring by pulling it outward.
5. Pull the slide back as if to put the pistol into battery and then move the slide forward and position it so that the indentations on the right side of the receiver and slide are lined up.
6. Rotate the barrel in a counterclockwise direction to the limit of its movement.
7. Lastly pull the slide in the barrel forward and off of the receiver.
Spanish Handguns by Gene Gangarosa
Astra automatic pistols by Leonardo Antaris
The standard directory of proof marks by Gerhard Wirnsberger
Official guide to gunmarks by Robert Balderson