The tracer projectile having a closure disk assembly is described. The tracer projectile includes a projectile base with a tracer cavity formed therein. A pyrotechnic charge is pressed into the tracer cavity and is ignitable by burning propellant such that a trajectory of the projectile is visible when fired. A closure disk assembly covers and seals the tracer cavity. A crown of the closure disk assembly is supported on a ring flange formed by an annular groove in the projectile base. A sidewall of the closure disk assembly surrounds the ring flange. A retaining element is disposed in the annular groove and engages a rim of the closure disk assembly for securing the closure disk assembly to the projectile base over the tracer cavity.