There was probably some debris in the hammer or its immediate area or possibly in the hands slot in the frame. Plus, as mentioned the 2 mating surfaces between cylinder and extractor star need to be kept clean,
Always eject your empties with the muzzle well elevated in a safe direction, that way burned powder debris is more likely to fall away than land in that are and become trapped.
Always eject your empties with the muzzle well elevated in a safe direction, that way burned powder debris is more likely to fall away than land in that are and become trapped.