An endoscopic shaft assembly includes: an elongate outer shaft; and an outer housing coupled to a proximal portion of the elongate outer shaft. The outer housing includes: a tubular wall defining a cavity; and a shaft plunger disposed within the cavity and configured to move axially within at least a portion of the cavity along a travel path. The shaft plunger includes a collar. The collar is configured to be separated from the tubular wall along a first travel portion of the travel path and to contact the tubular wall along a second travel portion of the travel path.