It seems 37mm is about center for absolute co-witness. does anyone know what would be best for 1/3 co-witness from base to center? 45mm too high? This is for a 30 mm red dot. Thanks!
Why would you need the measurement?
Mounts for AR red dot sights are either Cow witness or lower 1/3.
I have one on the way that’s 45mm from base to center. It seems it may be a little too high. I’ll know once it arrives and I mount it up. I was just wondering if anyone had a handle on a relative height for the 1/3. Thanks
I had a thread around here discussing a fixed ring where we were talking about this, but I can’t find it now. You might get lucky searching for threads started by me in the optics section.
Let’s do the math…
If 37mm is center for absolute cowitness, then the irons are also aligned at 37mm. If you have a 30 mm optic, moving it up 10mm would put it at the lower 1/3 mark. That would be 47mm, so yeah giving it a little slack, 45 mm should be pretty close to lower 1/3.
Thanks LokNLod, makes sense…