Abstract: A broadhead assembly maintains the blades, pivotably mounted on an actuating plunger, in retracted condition until impact, thereupon thrusting them outwardly and forwardly for maximum effect, and ultimately constraining them against full retraction in a partially extended, optimal position.The blades have profile edges, including a locking section and a thrust section, which engage a positioning element to extend the blades, and to constrain them against full retraction, respectively. The assembly may additionally include an elastically deformable element for engaging the blades in their closed position, and it may also include a pair of fixed blades mounted adjacent the rearward end of the body.