Fired at the muzzle, a representative .30-06 load (9.7 g, FMJ, 880 m/s) reaches roughly 17 mm (0.7 inches) into kevlar nij iii. That is enough to defeat a typical barrier of this material — treat anything behind it as exposed.
About Kevlar NIJ III
A soft body-armor panel is roughly 5 mm of layered Kevlar.