Fired at the muzzle, a representative .30-06 load (9.7 g, FMJ, 880 m/s) reaches roughly 465 mm (18.3 inches) into drywall (gypsum). That is enough to defeat a typical barrier of this material — treat anything behind it as exposed.
About Drywall (Gypsum)
One sheet of interior drywall is ~13 mm; a wall is two sheets and a gap.