[jgand72]

a

 

[JTJ]

3/4" will give you a center co witness with the dot on top of the post.

 

[jgand72]

2

 

[connectegr]

Why such a high riser? I am mounting a similar Sig Red Dot this weekend. What is "1/3 co witness"?

 

[purehavoc]

Why such a high riser? I am mounting a similar Sig Red Dot this weekend. What is "1/3 co witness"?

 

[connectegr]

I was planning to use "absolute cowitness", iron sight and red dot both centered on top of post. What is the advantage of using the lower 1/3?

If I use absolute cowitness, is a riser necessary? Is so, how much?

 

[purehavoc]

I was planning to use "absolute cowitness", iron sight and red dot both centered on top of post. What is the advantage of using the lower 1/3?

If I use absolute cowitness, is a riser necessary? Is so, how much?

its really personal preference , I prefer the lower 1/3 because when I use the RDS I dont have all that sight taking up the whole sight picture . and when I do need to use my irons my RDS wont be on anyway . Either way I have more sight picture thru the RDS with lower 1/3 . again its really personal preference

 

[Quentin]

I also use the bottom 1/3 cowitness for the reasons purehavoc stated. I can look over the irons and just use the dot or look through the aperture and lollipop the dot on the front sight. One disadvantage of absolute is the red dot appears to dim when looking through the aperture - this is very noticeable to me.

 

[jgand72]

a

 

[jgand72]

a

 

[Quentin]

Oh and another question, which may be a stupid one, but will I need a cheek riser? I have no experience with using risers.

I doubt it, just the 1" riser for bottom 1/3...

 

[connectegr]

Is a 1/2" riser enough for absolute cowitness?

 

[JTJ]

Is a 1/2" riser enough for absolute cowitness?

The TRS25 takes a 3/4". A 30mm will take a 1/2".

 

[connectegr]

I have sig STS 081. Does that need 3/4 for center cowitness?

 

[Quentin]

I have sig STS 081. Does that need 3/4 for center cowitness?

Does it have a standard AR rail and sight height? If so that should work.

 

[connectegr]

No luck finding a 3/4 riser. Bought a 1/2 riser, but it appears closer to 3/4. And it lined up perfect cowitness. No for a few hundred rounds down range. Thanks for the input.