Fired at the muzzle, a representative 6.5 Creedmoor load (9.1 g, BTHP, 800 m/s) reaches roughly 313 mm (12.3 inches) into red brick. That is enough to defeat a typical barrier of this material — treat anything behind it as exposed.
About Red Brick
A single wythe of red brick (~90 mm) is typical of older exterior walls.