A device for inserting a marker into tissue at a biopsy site including an elongate shaft that moves conjointly with a plunger, and a spring secured to the distal end of the shaft. The device may comprise a cannula configured to receive a distal end of the shaft, and with a crimp, dimples, or other features formed near the shaft's distal end. The cannula may comprise a lateral aperture where a marker may be ejected from the lumen thereof. A ramp portion may be formed in communication with the lateral aperture, and the ramp portion may comprise a preselected slope that controls the angle at which the marker is ejected.