This is not really a defensive rifle setup (being a .22) but more of a fun plinker/rimfire 2 gun match setup, but I wanted to be able to co-witness Tech Sights (aperture style sight) with a red dot on the 10/22. I am using the OEM 10/22 sight base that has the 3/8" "inside" dovetail rail and the wider (weaver style) outside rail. I have a Bushnell TRS-25 micro dot sight mounted to the weaver style portion of the rail. This is the key to this setup.......the rear Tech Sights I have mounted are the one made for the Marlin 795 since it is made to fit the 3/8" built-in receiver rail on the Marlin 795. Tech-SIGHTS Precision Shooting Accessories
The rear Tech Sight made specifically for the 10/22 has a base that is designed to screw into the two rear receiver mounting holes on the 10/22 so I could not use those for this application since the rail uses all four mounting holes, other wise they are the same. The front sight is the standard 10/22 Tech Sight front sight. I now have true almost "absolute" center co-witness with this 10/22 setup. I have bore sighted the Tech Sights and red dot and I think it will work really well. I will try it out this weekend and do my "real" sight in.