The Mechanical ejector is a spring loaded blade of steel that rides in a relief cut in the bolt, as the bolt is pulled back with the case captured in the “controlled” feed the blade will physically push the case out of the action, the force of ejection depends on the effort of bolt operation. This is another holdover or benefit from military bolt action rifles like the Mauser which provides 100% reliable ejection of fired cases from the action.

Plunger style ejectors (on a “push feed” system depend on a spring loaded plunger to push the case clear of the action and sometimes weaken and barely clear the action or worse seize up in the retracted position and provide no ejection. They can even seize in the extended position and not allow bolt to close on the case. There are debates about the effects on accuracy of the constant pressure of the plunger on the case head as opposed to the mechanical ejector which does not contact the case head when in battery.