I will prove my newbie status with AR platform and red dot with the following maybe silly questions. But here goes!

My question is on zeroing both the red dot and the iron sites.

Is it possible to with absolute co-witness to use the red dot and zero it. Then simply adjust the front and rear iron sites to match the red dot location with a natural cheek weld hold. That is use the best as possible identical cheek weld used when zeroing the red dot. And then adjust the front and rear iron to “match” the dot?

Or must you remove the red dot and zero the iron sites traditionally. Then mount the red dot and again zero it?

Or can you simply with 0X red dot. Turn it off and zero the iron sites “as if” the red dot is not there. And then turn on the red dot and zero it (can you adjust the red dot to the irons to get “close” and then shoot some rounds to zero the red dot?

I hope this made sense

BTW. I have a SIG Romeo 5XDR zero mag red dot. It comes with Mount for either absolute or lower 1/3 witness. I like a tight low cheek weld so prefer to keep the red dot low in absolute co-witness. Subject to change as my experience changes with time!

I owned the gun first. The iron sites were zeroed in perfect. Then I added a red dot and adjusted it to cowitness. They both work perfect.

I guess you could do it visa versa. What's the difference if the gun hits the bull?

Kinda my thoughts exactly.

I figure the precise small dot and target is a more accurate way to site in. Then adjust the iron sights front and rear to adjust iron sights.

I can then verify the iron sights zero by turning off the dot and firing several rounds using just the iron sights “seeing through” the empty glass of the turned off optic.

You can zero the irons with the red dot mounted.

How well your absolute co-witness works may depend on the height of your riser. The 5XDR has riser the ability to be set up for a absolute cowitness (1.41"), or 1/3 lower cowitness (1.63") height. Make sure it is set up for absolute if that is what you want.

The integral site is set up for absolute co-witness. And there is an additional riser for lower 1/3.

I for the life of me don’t understand why anyone would want the higher mounting. But I guess different strokes for different folks.