Rachel Uchitel not only pulled out a gun on Wednesday ... Tiger's pilgrim mistress mercilessly opened fire on an unarmed target -- all for her private detective course ... and she CRUSHED IT.
Rachel tells TMZ, she's a week away from finishing up private investigator school -- and acing her target-shooting exam was par for the course.
Sources at DGA Detectives Academy in Agoura Hills, CA tell TMZ, Rach shot a PERFECT 250/250 on the range with a Glock and a .38 Special revolver.
We're told she's working on getting whatever gun permits she needs as a P.I. -- including both exposed and concealed weapons permits. Pretty badass.