An apparatus for operating on tissue includes an end effector, an actuator, and a spring assembly. The end effector includes a first jaw and a second jaw that pivots relative to the first jaw from an open position to a closed position. The actuator is coupled with the second jaw to pivot the second jaw relative to the first jaw. The spring assembly is coupled with the actuator and is adjustable from a first position to a second position. The spring assembly compresses to resiliently bias the actuator to pivot the second jaw to the open position when the spring assembly is in the first position. The spring assembly compresses a smaller amount when the spring assembly is in the second position.
