So, In 2012-14 I made a few (3) reflex sight clones but never clicked enough photos to show the whole process or working model.
I disposed them off when my rifle's piston broke
The above are the 2 types of design I thought of and the only photo of one of my reflex sight mounted on an air rifle, which is powered by 9 volt battery
maybe you guys could improve upon them and come up with something better
Step 1: The Process
The above photos are the only things left of the reflex sight.