A dispensing pump includes a polymer compression spring assembly, base vents and a flow baffle. The dispensing pump includes a pump base, and a dispensing head having a piston stem. The polymer compression spring assembly includes a slotted tubular spring element and first and second loading cones received at opposing ends of the slotted tubular spring element. The venting ports allow air to escape when capping the container after filling and the flow baffle reduces or prevents the product from being pulled into the pump accumulator before residual air (headspace) has been evacuated from the container during the initial priming strokes.