III. Firearm Information by Type

C. Semi-Automatic Pistols

2. Models and Manufacturers

ab. Astra

1. Polishing the Astra A-75 Trigger
by nemesis@enter.net

Disclaimer: Do not perform the procedure described in this article unless you are fully qualified to do so, with formal training in such procedures. Furthermore, consult with a gunsmith before (and after) doing any modifications to a firearm. The author and the FAQ maintainer are in no way responsible for people who misuse this information.

Disassembly of hammer

  1. Remove magazine and unload chamber.
  2. Pull out slide release and remove slide assembly.
  3. Use a hollow ground screwdriver to remove grip panels.
  4. Pull out decocking lever.
  5. Draw back the hammer beyond full cock and note the small hole in the hammer spring strut. This will be visible in the small cut out on the left grip frame near the magazine well. Insert a small paper clip and release pressure on hammer. Hammer spring assembly should now be loose, hammer is no longer under spring tension.
  6. Push hammer pin (exposed by removal of decocking lever) out of the frame from the left side.
  7. Remove hammer. If firing pin safety cam falls out remember to replace it before reinstalling hammer.
Reassemble in reverse order

Having removed the hammer take a very fine jeweler's hand file and smooth away the parkerized surface of the full cock notch leaving a bright polished surface without rough spots. Be very careful not to shorten or change the angle of the notch.

The sear is exposed when the hammer is removed and can be polished without removing it from the frame. Using a thin flat file polish off the parkerized coating on the nose of the sear. Again be careful not to change the shape of the bearing surface on the sear.

After the gun is reassembled dry fire it one hundred times in the double action mode and another hundred times single action. This will test the functioning of the job and help wear-in the contact surfaces evenly. Now cock the gun and hold the hammer, press in the firing pin with a thin rod. It should not travel forward freely unless the trigger is fully retracted. This tests the firing pin safety. With the gun fully cocked, attempt to make the hammer fall by wiggling and pushing the hammer. Toss the cocked gun several feet onto a sofa cushion, slap it around. The hammer should not drop. Drop the hammer using the decocking lever, it should be caught at half cock every time. If the gun passes these tests it is safe to reload and carry.

Note: The fact that the bearing surfaces of the hammer and sear were parkerized surely accounts for the rough trigger pull that this otherwise fine pistol had. After the job the single action trigger pull was still long and mushy but at least it was not rough and the let-off was crisp. Since this pistol was not designed as a target gun I would not advise doing any further mods on the trigger. There was also quite a bit of polishing compund (too dry and gritty to be grease) caked around the interior, rinsing out with WD40 might not be a bad idea.