New to Red Dot Sights: Questions for the Experienced

[Uni-Vibe]

I just put a 2 MOA red dot on my M4gery. I have not sighted it in yet. It co-witnesses with the A2 front sight and the BUIS rear sight (if the rear is flipped up). I also have an extender that will raise it a half inch if I want to.

Question: It it better to have the red dot co-witness with the front sight, or raise it a bit so it clears the front sight?

[1168]

I like a lower 1/3 co-witness, just to get the optic up a little higher (Larue). But co-witness in general is a good thing because if your optic takes a crap or your battery dies at an inopportune time, you can still get hits up close with no delay using the optic as a ghost ring.

[GH41]

I just put a 2 MOA red dot on my M4gery. I have not sighted it in yet. It co-witnesses with the A2 front sight and the BUIS rear sight (if the rear is flipped up). I also have an extender that will raise it a half inch if I want to.

Question: It it better to have the red dot co-witness with the front sight, or raise it a bit so it clears the front sight?

To me co-witness is overrated. If you are using a RDS correctly you are looking way past the front sight. The best way to learn how to shoot a dot sight is with the front cap down or taped up. Fit a mount the correct height for the way you shoot and don't worry about Co-witness.

[Uni-Vibe]

To me co-witness is overrated. If you are using a RDS correctly you are looking way past the front sight. The best way to learn how to shoot a dot sight is with the front cap down or taped up. Fit a mount the correct height for the way you shoot and don't worry about Co-witness.

That's what I was thinking. I already have a Magpul BUIS rear sight installed, and sighted in. If the red dot quits, I can flip that up and keep on going.

[sniperfrog]

To me co-witness is overrated. If you are using a RDS correctly you are looking way past the front sight. The best way to learn how to shoot a dot sight is with the front cap down or taped up. Fit a mount the correct height for the way you shoot and don't worry about Co-witness.

Some people, like me, can’t do this. When I close the cover on a red dot I get a large shift in how I see the dot. Yes, I’m using both eyes open with a target focus but for whatever reason the dot will shift about a foot to the right at 10yards. If I put the rifle in a rest and put the dot center mass and just open and close the cover I can see the dot shift back and forth. I’ve seen the term phoria used to describe this but I’m not sure that’s accurate. I’ve seen a lot of others that have the same problem.
I have no problem using an RDS with both eyes open. I shoot high magnification scopes with both eyes open. But close the front lens cover and I ain’t hitting anything.

[Mysteryman]

Some people, like me, can’t do this. When I close the cover on a red dot I get a large shift in how I see the dot. Yes, I’m using both eyes open with a target focus but for whatever reason the dot will shift about a foot to the right at 10yards. If I put the rifle in a rest and put the dot center mass and just open and close the cover I can see the dot shift back and forth. I’ve seen the term phoria used to describe this but I’m not sure that’s accurate. I’ve seen a lot of others that have the same problem.
I have no problem using an RDS with both eyes open. I shoot high magnification scopes with both eyes open. But close the front lens cover and I ain’t hitting anything.

Phoria is the phenomenon. Basically it refers to your eyes alignment. With the cap closed your non sighting eye is the sole source of spatial data. If your eye alignment is out of wack then you will have a poi shift.

[1168]

Are we talking about lollypopping the dot on the front sight post, or are we talking about being able to use your irons through the optic?

[Uni-Vibe]

Are we talking about lollypopping the dot on the front sight post, or are we talking about being able to use your irons through the optic?

Little of both. The way the factory red dot setup is, it puts the red dot right atop the front sight. What I need to know is, is this necessary or desirable? Could I use the red dot better if I raised the optic a bit, so it didn't co-witness?

I can use the irons through the optic if necessary in either position.

[grizzman]

If your RDS isn't a piece of junk that's guaranteed to fail, there's little benefit to absolute co-witness.

Having said that, it sounds like you've already got the spacer so you can test this yourself. Feel free to try both heights and use the method you like. There's no wrong answer.

[ggammell]

So let me get this straight...

You’ve been a member here for 11 YEARS and you just now put your first red dot on a rifle? Better late than never.