Abstract: A safety plug device (10) for the firing chambers (101) of firearms (100) such as pistols (100') and rifles (100") wherein the safety plug device (10) comprises a stepped shoulder generally cylindrical plug member (13) having a tab member (16) with an enlarged flag portion (17) formed on its upper end; wherein, the plug member (13) and a portion of the tab member (16) are dimensioned to be received in the firing chamber (101) while flag portion (17) will project a substantial distance above the slide bolt mechanism (103) of the firearms (100) to indicate that the weapon is unloaded.