This Weihrauch HW99S has been fitted with diopter sights. They work very well, but being primarily designed for use on PCPs with no recoil. The scope rail clamp is very short, and even doing it up as tight as possible without stripping the thread, it was still creeping backwards after 20 minutes of firing, which affects zero. More detail on this later, but we modified the sight unit to accept a stainless steel bolt to engage with the HW recoil stud holes. which has remedied the issue.

HW diopter creep issue

HW diopter creep issue resolved