Sighting in a red dot scope

[Lexicon Devil]

After sighting in at 20', I sent the target out to 75' for some fine tuning, I find I'm hitting about 7-8 inches higher, and I was starting to get frustrated. I pretty much had to shoot at the bottom of the target to get anywhere near the center. What am I doing wrong?

[hermosabeach]

First off-
What firearm?
What red dot?
How many MOA?

[Junkie]

Not a big surprise. The height over bore is 2.5-2.75" depending on what red dot. Because I'm lazy, I'll pretend there's no drop at the distances you're talking about, so the bullet is moving up 2.5" in 20' or 1" per 8' (or more if the optic is higher). That works out to around 7" by 75'. Sighting in that close causes problems because of how steep the angle is.

[Hairball]

Well, why would you start out with your initial sight set at 7 yards? Going out to 25 yards is not going to be anywhere near point of sight/point of impact as the round is still on its way up. Most people with red dots will either sight them in at 50 yards or 100 yards. I set all of mine at 50 yards.

[Lexicon Devil]

Oh sorry...

It's a SIG MCX .223/5.56 with a StrikeFire II that's 4 MOA

[Lexicon Devil]

Well, why would you start out with your initial sight set at 7 yards? Going out to 25 yards is not going to be anywhere near point of sight/point of impact as the round is still on its way up. Most people with red dots will either sight them in at 50 yards or 100 yards. I set all of mine at 50 yards.

This is my first time using a scope like this, so I was kind of going in blind. The man at the range counter told me how I should do it when I asked him for tips. This was the end result.

[Hairball]

Do you want to use the optic only or set it with the iron sights so they match?

[Lexicon Devil]

Do you want to use the optic only or set it with the iron sights so they match?

I want to set it with the iron sights. It's called Co-witness, right?

[Hairball]

Yes, I could type it all out but it's much easier for you to do a Internet search on how to co-witness iron sights with red dots and you will find all kinds of information. The only down-side to co-witnessing for some shooters is that they get too wrapped up in looking through their peep sight to see the red dot. That is not how red dots are designed to be used as most people close an eye to look through the sights/tube while you really want to leave both eyes open. Many will co-witness in case their red dot goes down during a fight but whether you need to really worry about that situation is up to you and what you feel is important in setting up the optic.

Edit: are you running fixed or pop-up sights

[russ69]

After sighting in at 20'....What am I doing wrong?

Sighting in at 20 feet.

[vinny_land]

https://www.ar15.com/mobile/topic.html?b=3&f=18&t=529846

50/200 yard zero with my Aimpoint Comp ML3. Use whichever target to fit your needs.

[FMFdevildoc]

I would recommend return the red dot back to mechanical zero. Start at 50yds then walk it out to 100, also be mindful of the MOA of the dot. For example, on my Vortex StrikeFire it has a large (3moa) dot. Once I got 3 shot groups in 2-3in or less, I left it as-is. All I need it to shoot is "minute of coyote" and "minute of ground squirrel".

As mentioned; details on caliber, make/model of red dot may be able to garner more appropriate field reports and DOPE...

[Lexicon Devil]

https://www.ar15.com/mobile/topic.ht...&f=18&t=529846

50/200 yard zero with my Aimpoint Comp ML3. Use whichever target to fit your needs.

This is great. Thanks.

[Lexicon Devil]

I would recommend return the red dot back to mechanical zero. Start at 50yds then walk it out to 100, also be mindful of the MOA of the dot. For example, on my Vortex StrikeFire it has a large (3moa) dot. Once I got 3 shot groups in 2-3in or less, I left it as-is. All I need it to shoot is "minute of coyote" and "minute of ground squirrel".

As mentioned; details on caliber, make/model of red dot may be able to garner more appropriate field reports and DOPE...

This works too. Much appreciated

[Lexicon Devil]

Yes, I could type it all out but it's much easier for you to do a Internet search on how to co-witness iron sights with red dots and you will find all kinds of information. The only down-side to co-witnessing for some shooters is that they get too wrapped up in looking through their peep sight to see the red dot. That is not how red dots are designed to be used as most people close an eye to look through the sights/tube while you really want to leave both eyes open. Many will co-witness in case their red dot goes down during a fight but whether you need to really worry about that situation is up to you and what you feel is important in setting up the optic.

Edit: are you running fixed or pop-up sights

I found an old thread with info.
I'm running pop up sights.