A surgical instrument includes a housing, a shaft extending distally from the housing, an end effector assembly at a distal end portion of the shaft, and a drive assembly. The drive assembly includes a movable handle, a carriage operably coupled to the movable handle, an inner drive operably coupled to the end effector assembly, and a spring assembly operably coupling the carriage and the inner drive. The spring assembly includes inner and outer coil springs arranged in a nested configuration. Initial actuation of the movable handle slides the carriage such that the spring assembly transfers the sliding of the carriage into translation of the inner drive to apply a jaw force by the end effector assembly. Subsequent actuation of the movable handle slides the carriage to compress the spring assembly to substantially maintain a position of the inner drive, thereby controlling the jaw force.