SGT_geardo said:
Why not co-witness? I did with my M4 and it worked just fine.
...reflex and holographic sights allow you to shoulder your weapon...rapidly acquire your target and fire...eye position...head position and a consistant cheek weld are not critical...you are focusing upon the target with both eyes...and looking through and past the optic...specifically the aiming tool...ie the reticle or dot...and not focusing on it...not even a little...it just happens to be there in front of your eye...as long as you can see the dot or reticle...you are good to go...
...when using iron sights...your eye and head position...along with a consistant cheek weld are critical...your pupil needs to be directly behind the irons..ie rear sight...aligning your front sight upon the target...this slows you down considerably...
...when you co-witness...you are using your irons and kinda forcing the "aiming tool of the optic" to be along the same line of sight as when using your irons alone...making your eye position ...head position...and cheek weld critical...you're basically using your irons while the dot will appear in your line of sight...assuming both are zeroed for the same range...not the proper way to use these optics...
...the optic is your primary...the irons are your back up sights "only"...and should be folded down so that you aren't distracted by the "optical clutter" they present in the optical window...for example...optical clutter may induce aiming error and also your confidence in a dynamic situation...thereby slowing down your ability to deliver deliberate aimed fire...