This invention is directed to a firearm safety device that has a chamber block for being received in a chamber of a firearm. An internal area is defined in the chamber block and can receive a bullet so that the bullet biases the outer walls outward. A visual indicator is attached to a distal end of the chamber block and is received in the bore of the barrel and extending outward past the muzzle providing a visual indication that the firearm is in a safe condition. In one embodiment, the chamber block can be inserted into the muzzle and the visual indicator extends through the barrel and chamber and out of the ejection port of magazine well. The visual indicator can be modifiable in length to accommodate various lengths of barrels and can be flexible.