Fired at the muzzle, a representative .357 Magnum load (10.2 g, SP, 395 m/s) reaches roughly 25 mm (1.0 inches) into polycarbonate. That is enough to defeat a typical barrier of this material — treat anything behind it as exposed.
About Polycarbonate
A polycarbonate pane (~12 mm); true bullet-resistant glass is far thicker and layered.