A receiver comprises an interior space comprising a longitudinal central axis and a receiving end, a first set of first structures, and a second set of second structures. The first set of the first structures is positioned closer to the receiving end of the interior space than the second set of the second structures. The first set of the first structures has a first axial compliance coefficient along the longitudinal central axis of the interior space. The second set of the second structures has a second axial compliance coefficient along the longitudinal central axis of the interior space, such that the first axial compliance coefficient is greater than the second axial compliance coefficient.