Fired at the muzzle, a representative .40 S&W load (11.7 g, FMJ, 300 m/s) reaches roughly 16 mm (0.6 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.