MBUS co-witnessing question

[Policetacteam]

Will a rear MBUS + Yankee Hill Machine EOTech riser + nonraised EOTech co-witness with a standard A2 fixed front sight. I would think that everything would coexist and work but curious if anyone sees any isses here.

[Eric]

The YH riser will elevate the EOtech so that you will have the irons closer to the lower third of the optic, instead of a true co-witness.

[Policetacteam]

Thanks Eric,

I may have not been clear. If the MBUS is mounted directly to the rail of the upper receiver will it still co-witness the bottom 1/3 of the sight picture and line up with the front sight or would the MBUS need a riser!?!

[Beaux]

They do on the bottom 1/3 with my EOTech 557 mounted without a riser.

[rob_s]

Iron sights work independent of the Eotech. If the MBUS is mounted to the flattop upper and works with the FSB when there is no optic, and the optic itself is not mounted so high as to block the iron sights, then the irons will cowitness with the optic.

[m24shooter]

Your question is a little confusing: you mention a YHM riser and then say a nonraised EOThingy. I take this to mean that the EOT is actually raised because it is on top of the YHM riser. Correct?
If I'm tracking, then your MBUS will be on the same plane as long as they are mounted on the upper and your forward rail which are at the same height. With the EOThingy on the riser, the irons will be visible in the lower third.
This is called a lower third cowitness as oppsed to an absolute cowitness, which would have the irons in the center of the EOThingy FOV.

[rob_s]

Pictures would help a lot.

[Policetacteam]

Ok...I have to apologize for not being more clear on my description. Maybe this will clear up the confusion. By nonraised EOTech I meant an EOTech without the 7mm raised base already on the unit itself. I realize that you wouldn't need an YHM raised base if you were using a raised EOTech but I thought I would throw it in there to eliminate any confusion. I think most of the responses have answered my question. Thanks for the help!