Samples are recoverable from very dense tissue utilizing an instrument incorporating a capture component formed with leafs extending to leaf tip regions supporting a stainless steel pursing cable assembly. The cables of this assembly are electrosurgically excited to define a confronting leading edge and extend rearwardly to a terminator component. Motor drive is imparted to the capture component to deploy the leafs at a substantially constant initial angle of attack. During this procedure the terminator component is drawn forwardly by the cable until encountering a cable stop whereupon continued motor operation loads the cables in tension. By applying a preliminary loading tension to the cables before encountering the pursing cable stop, the angle of attack of the leaf tip region is gradually altered to lessen the development of lateral tissue induced forces against the leaf structures.