Spray gun reservoir components are disclosed. The spray gun reservoir component includes a liquid outlet and an outer face, and defines a centerline plane and an attachment plane. The liquid outlet surrounds a longitudinal axis. The outer face extends away from the liquid outlet. The centerline plane passes through the longitudinal axis. The attachment plane is defined orthogonally to the longitudinal axis and the centerline plane. The outer face further comprises a retention feature extending away from the centerline plane and generally parallel to the attachment plane. In some embodiments, the spray gun reservoir component further comprises a bearing surface formed on the outer face along the attachment plane to engage with a corresponding bearing surface on a liquid spray gun attachment point, with the bearing surface comprising the retention feature.