A syringe includes a barrel having an internal surface defining an internal bore therein, and a plunger disposed within the internal bore of the barrel. A distal end of the plunger is inserted into a proximal end of the barrel. At least one radial projection is disposed on an external surface of the plunger, the at least one radial projection includes a proximal ramp and a distal ramp. The distal ramp includes a first point being a point of incipient contact with the internal surface of the barrel, and the at least one radial projection has a first slope relative to the longitudinal axis at the first point. The at least one radial projection has a second slope at a second point along the proximal ramp. An absolute value of the first slope is different from an absolute value of the second slope.
