Usefulness of absolute co-witness

ST19AG_WGreymon · Apr 14, 2014

I'm trying to decide on an red dot for my AR with a fixed front-sight post and a BUIS. At the moment I'm trying to wrap my head on whether it should be 1/3 co-witness or absolute co-witness. My thoughts are that with although absolute is nice you have a large part of your sight picture taken up by the front sight post. What are your thoughts on the pros and cons thereof and it's usefulness with regards to homedefense and range use up to 100-300m?

Flipz · Apr 14, 2014

If you have a FSB you should definitely use lower 1/3 in my opinion. I even use lower 1/3 when using folding BUIS. But that's a personal preference as I like the cheek weld better. If you use absolute co-witness on a rifle with a FSB your field of view through the optic will be dramatically diminished. You should stop by a shop that has both options and see for yourself.

erwos · Apr 14, 2014

Fixed front post = go with lower 1/3

hogarth · Apr 14, 2014

Agreed. With the fixed post, go with lower 1/3. For folding irons, I prefer absolute, which allows everything (cheek weld and such) to be absolutely the same whether you are using irons or red dot.

Mickey the Dragon · Apr 14, 2014

Initially I was hesitant to jump on the lower 1/3 bandwagon, but I decided to take the plunge and got my Aimpoint H1 with the lower 1/3 mount and I'm really glad I did. I can still use the irons without any issues, but the field of view is much better when I'm using the optic.

JBinDC · Apr 14, 2014

How do you pick a centerline when doing lower 1/3rd? Ya just eyeball it?

ObsceneJesster · Apr 14, 2014

Lower 1/3rd for various reasons.

Sent from my SM-G900T using Tapatalk

Adam Conover · Apr 16, 2014

Go true Co-witness if consistency is important to you (Cheekweld and so on) and go lower 1/3 if you prefer the unobstructed picture of the dot being above the front sight. One is not any better then the other its all a matter of preference and also depends on your choice of optic, some optics will not give the option (for example I prefer to run the Eotech exps3-0 and because of the QD function it is raised to lower 1/3 but it is still not a problem to use the irons) In the end you cant go wrong with either set up

Sticky · Apr 16, 2014

erwos said:
Fixed front post = go with lower 1/3

hogarth said:
Agreed. With the fixed post, go with lower 1/3. For folding irons, I prefer absolute, which allows everything (cheek weld and such) to be absolutely the same whether you are using irons or red dot.

This for me.. I run fixed sights on my hbar with 1/3 lower CW and like it a lot. If I had flips and an rds, I'd go absolute. The difference in cheek weld is minimal for me when transitioning from one to the other...

SCARCQB · Apr 16, 2014

I run absolute co- witness. Everything lines up. Its a good teaching setup and being able to check on zero withoutbfiring a shot is an added bonus.

Same cheek weld, nose to harging handle.

Boom Boom · Apr 17, 2014

If you get a full-sized red dot (Comp M3/4, PRO, Eotech XPS, etc.), you can still go absolute and look through the top third of the glass. The red dot will float above the front post, very similar to a lower-third mount. In that respect, it's the best of both worlds, since your front post is still fully viewable/usable if you shift your sight plane to the center of the glass. If nothing else, an absolute mount encourages consistency. I don't have a strong preference either way. Both ways have pros and cons. Neither is a bad choice, except for mini red dots like the T-1/H-1. Absolute mount height sucks with mini red dot sights because the front post fills up way too much of the glass. But then a mini red dot sight with lower-third mount (some are closer to lower-fourth) can tend to make the front sight almost unusable, to the point of me avoiding the purchase of more mini red dots.

Usefulness of absolute co-witness

The #1 community for Gun Owners of the Northeast

Member Benefits:

ST19AG_WGreymon

Ultimate Member

Flipz

Ultimate Member

erwos

The Hebrew Hammer

hogarth

Ultimate Member

Mickey the Dragon

Ultimate Member

JBinDC

Ultimate Member

ObsceneJesster

Ultimate Member

Adam Conover

Member

Sticky

Beware of Dog

SCARCQB

Get Opp my rawn, Plick!

Boom Boom

Hold my beer. Watch this.

Users who are viewing this thread

Latest posts

Forum statistics

Latest threads

Forum statistics

Share this page