Co-Witnessing questions

[MisterTFM]

Found this on another thread:
Depends on if you want absolute co-witness or lower 1/3 co-witness.

For absolute, go with the medium height, .83". For lower 1/3, the 1".

~~~

Could somebody please explain exactly what 1/3 co-witness means and why would you want that method over absolute?

I'm trying to mount a Bushnell TRS-25 and trying to determine what riser I need. I'm also looking for a Quick Detach feature on the riser.

Thanks.

 

[sithlord]

Simply put -

Absolute co-witness puts the red-dot on target and in the center when the iron sights are in the center. This allows you to have proper cheek welds and consistent views all of the time. However, the iron sights may obscure some of your view.

1/3rd co-witness puts the red dot on target, and allows you a greater field of view, at the expense of having different cheek welds depending on whether you are using your red dot or your iron sights.

Personally, with flip ups, I use absolute co-witness, and leave the iron sights down. This allows me a consistent cheek weld, and the irons do not obstruct the field of view.

 

[coachray]

Simply put -

Absolute co-witness puts the red-dot on target and in the center when the iron sights are in the center. This allows you to have proper cheek welds and consistent views all of the time. However, the iron sights may obscure some of your view.

1/3rd co-witness puts the red dot on target, and allows you a greater field of view, at the expense of having different cheek welds depending on whether you are using your red dot or your iron sights.

Personally, with flip ups, I use absolute co-witness, and leave the iron sights down. This allows me a consistent cheek weld, and the irons do not obstruct the field of view.

That's how I roll also

 

[just plain joe]

Some of us prefer the "lower 1/3 co-witness" as the field of view is less "busy".

Find out what works best for you and drive on.

JPJ

 

[dingode]

I'm with Sithlord. I have the MOE edition so I just flip the sights down when not in use. Absolute co-witness works the best for me.

 

[MisterTFM]

Thanks for the explanations.

I ordered a UTG .83 QD riser today and will try the absolute co-witnessing as a start.


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[WR Moore]

The difference between the two often depends upon your cheek weld. If I'm low enough to index my irons, the red dot is on the front sight. If I'm up a bit, it looks kinda like the lower third version.

 

[c p ron]

Thanks for the explanations.

I ordered a UTG .83 QD riser today and will try the absolute co-witnessing as a start.


Sent from my iPhone using Tapatalk

I'm thinking of doing the same as you TRS 25 UTG.83 QD riser.
Just wondering how it all worked out.

Thanks
CP Ron

 

[tracksol]

Lower 1/3 became popularized with special forces, specifically SOCOM since the M4 SOPMOD program, with it's accessories and red dot optics ame from them. Since at the time most M4 rifles had fixed front sights, the optics were mounted higher, hence "SOCOM height".

With a flip down front sight, the need for the lower 1/3 height is immaterial.

A rarely mentioned but good tip regarding absolute cowitness is that you can do a quick and dirty rough check of the zero of your red dot against the irons since they are on the same plane.

 

[MichiganScott]

I prefer the absolute co-witness regardless of whether or not the back up sights are in place. The absolute co-witness is similar to the circle within a circle sight picture that target shooters use. Your eye automatically places the red dot and target in the center. With the lower 1/3 co-witness you have to actively place the dot on target unless you have plenty of training with that sight picture.