Abstract: Ignition of a separating charge in a cavity between a flash-conducting tube and a casing of a propellant charge igniter extending below a combustible tube is brought about by the propellant gases passing through priming bores from the outside of the propellant charge igniter to be used in a breech of a cannon or like weapon. This requires a seal acting in the manner of a valve being positioned at the flash-conducting tube head and being urged towards the casing. An especially suitable sealing means in a sealing ring located in an annular groove having a cross-section shape similar to a trapezoid. In case, for example, on account of low temperatures, the pressure buildup of the propellant gases occurs more gradually, the separation of the combustible tube from the bottom piece is thereby also automatically initiated at a later point in time. Thereby, flashback in the breech zone of the cannon is avoided and ballistics are improved.