Barrel pin assemblies

A cylinder lock, comprising:

• a. a barrel having an axial keyway and a plurality of barrel bores extending radially from, and in communication with, the keyway, the barrel being selectably rotatably movable within a cylindrical housing;
• b. the cylindrical housing having a column with a plurality of column bores extending radially from said barrel comprising a barrel pin assembly slidably movable within a barrel bore, wherein
• the barrel pin assembly comprising at least two, non-concentric engaging proximal ends, configured, when engaged by a key having at least two engagement sites, to slidably and independently translate along the barrel bore's longitudinal axis to a shear line against a single nested column pin assembly located in a corresponding column bore;
• and wherein
• the nested column pin assembly comprises an axially interrupted cylindrical housing defining a longitudinal axis and having a closed distal end and an open proximal end, the closed distal end defining a concentric aperture, wherein the axially interrupted cylindrical housing is sized and configured to accommodate an axially movable piston;
• c. a stopper disposed at the distal end of each column bore;
• and
• d. a biaser disposed within each column bore, sized and configured to bias the nested column pin assembly towards the barrel.