Best distance to sight in AR Iron sights?


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DDawg
March 14, 2011, 09:51 PM
I've got a flat top AR with a fixed front sight and flip up rear( no elevation adjust on rear). Eventually im gonna put some type of optics on it, but until i decide which I'm gonna shoot irons.
Im shooting .223 55 gr FMJ, and just gonna do fun shooting at various distances (with Irons). I know traditionally sighting in is done at 100 yds, but i can barely see the big black circle, let alone the bulls eye at that distance.

So what distance should use to sight in Irons, or does it even matter?

Thanks
DD

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GCBurner
March 14, 2011, 09:57 PM
For the A2 type iron sights, there's a mark on the drum to be used for sighting in at 25 yards/meters. You set it there, and adjust the elevation by screwing the front sight up or down. Once the front sight is set, the rear sight elevation markings should get you on target out to 600-800 yards/meters, depending on what your rear sight goes up to.

DDawg
March 14, 2011, 10:03 PM
Thanks for the reply, Ive read about the 25 meter battle sight zero, But The rear sight does not have any way to adjust for elevation.

Thanks

Sky
March 14, 2011, 10:59 PM
rule of thumb is 25 = 300 and 50 = 200. Front sight is used for elevation. When you get your optics do the same thing. I always get on paper at 25 meters or 27 yards or closer then do the final zero for the rifles intended use. red dots for me out to 200 so 50 zero. High power scopes on my long barrels are all zeroed for 300 yard hits.

GCBurner
March 14, 2011, 11:01 PM
Thanks for the reply, Ive read about the 25 meter battle sight zero, But The rear sight does not have any way to adjust for elevation.

Thanks
If you sight in at a 25 meter target, with a 6 o'clock hold hitting the center of the bullseye, you should be in the black on the target out to 300 meters with a .223.

Double Naught Spy
March 15, 2011, 01:47 AM
So what distance should use to sight in Irons, or does it even matter?

rule of thumb is 25 = 300 and 50 = 200.

For my needs, 50 is much better. I rarely shoot beyond 100 with iron sights and so a 50 zero gives me a flatter trajectory of consideration over the 200 yards than what I would get with a 25 yard zero.

See data shown here...
http://www.ar15.com/forums/topic.html?b=3&f=118&t=392319

With a 50 yard zero, 55 grain ammo will not be more than 1.6" higher or lower than the point of aim from 20 yards to just over 220 yards. With 62 gr. ammo, you won't be more than 2.1" away from POA from 10 yards to beyond 250.

A 25 yard zero will give you the higher arc needed to better make 300, but will me that the bullet ventures even further from the POA such that you may need to make some Kentucky windage and elevation corrections for more precise shooting at intermediate points.

If you don't need to shoot 300 yards, I think the 50 yard zero is better. If you only need to shoot 300 very irregularly, then maybe that is where you want to apply KW&E corrections instead of at shorter distances.

That is my opinion based on my shooting needs and likes. I am not suggesting that anyone else is wrong or that the setting I use is superior. It is just what works best for me.

Onmilo
March 15, 2011, 10:03 AM
If you are using a fixed non elevation adjustable rear sight then a fifty yard/meter zero is best.
Use the smaller apeature and regulate using the front sight.

If you are using an A2 type adjustable sight or a back up iron sight using the A2 style of elevation and windage then a 25 meter zero is what you want as it will correctly regulate the elevation settings.
Use the smaller apeature, set the rear sight to the 6/3 or 8/3 setting and regulate with the front sight.

If you are using a back up iron sight using any other type of elevation settings, these are generally zeroed at 100 meters using the 100 meter setting and fine regulating with the front sight again.

Windage is, of course, always adjusted at the rear sight.

M1key
March 15, 2011, 04:43 PM
Another vote for 50yd zero.

M

benzy2
March 15, 2011, 06:17 PM
The real question is how far do you plan to typically shoot? Sight in for that. If you have an A2 rear sight, sighting in at 25 on the drum will get you, as others have said, a fairly accurate elevation adjustment out to 600-700 yards. It sounds like you have a fixed elevation rear sight. In that case, sight in for what you plan to shoot at. If you never shoot to 100 yards, there is no point having it adjusted to 100 yards. On the same issue, if you never shoot 25 yards, why sight in for it (on a fixed rear sight)?

Quentin
March 15, 2011, 06:31 PM
50 yards is a good zero point since it's well suited for 5.56 ballistics, keeping POA and POI within about 2.5" from 0 to maybe 230+ yards. You'll be hitting within 2.5" low from 0-50 yards, dead on at 50 then up to 2.5" high after 50 to almost 200, dead on at 200 then dropping low again but probably within 2.5" until 230 or so yards then the bullet finally falls out of the flat trajectory.

SpaceMonkey
March 15, 2011, 10:51 PM
Best of both worlds from the old Maryland Shooter's site.

Slight modification to rear sight works very well.

http://grburnett.us/guns/ImprovedBattlesightZero.pdf

henschman
March 15, 2011, 11:07 PM
Or you could just zero the rifle with the small aperture at 25/300m, and flip to the big aperture if you want a 50/200m zero. Mr. Stoner thought of all this stuff way back when he designed the thing, and that is how it was made to be used.

LKB3rd
March 15, 2011, 11:49 PM
Or you could just zero the rifle with the small aperture at 25/300m, and flip to the big aperture if you want a 50/200m zero. Mr. Stoner thought of all this stuff way back when he designed the thing, and that is how it was made to be used.
Most sights have a tiny "z" which is either one or two clicks from bottomed out, If you zero it on that at 25 meters, then the 3,4,5,6, and 7,8 on the fixed handle sights should correspond to meters when using a milspec 5.56 x 45 round.
I can't remember if it is yards or meters, but the bottomed out 300 meter position should correspond to a 37 yard (or meter) zero.
Zeroing it at 25 or 50 bottomed out gets you pretty close to that anyway, but in my opinion taking advantage of the sights' design is a plus for some people. And it's easy :)
Best of both worlds from the old Maryland Shooter's site.

Slight modification to rear sight works very well.

http://grburnett.us/guns/ImprovedBattlesightZero.pdf
I have mine set up like this and haven't had a chance to test it out much beyond sighting it in at 50. It isn't as plug and play as the 25 meter "z" method, but if it works for me, it gives more options while retaining the built in 4,5,6, settings. Lots of net reports say it works great.

Double Naught Spy
March 16, 2011, 12:49 AM
Mr. Stoner thought of all this stuff way back when he designed the thing, and that is how it was made to be used.

While nice, multiple zero sights date way back to the 1800s IIRC, certainly the early 1900s.

Maverick223
March 16, 2011, 12:49 AM
I guess i'll be the odd man out, I prefer to sight in for 300yds, as most of my shooting occurs at 300yds (with the remainder at 50 & 100). Using 55gr. bullets at about 3300fps I have found that 30yds. gets me pretty close at 300 (but i'm not shooting an AR so my sight height may be a bit different leading to this value).

:)

kwelz
March 16, 2011, 12:52 AM
50 Yards is the common BZO for Police, .Mil and training.
It allows you to have a 50/200 zero and you can easily tell where you need to be at 25 as well. a strait 25 yard BZO is no where near as flexible.

Andrew Wyatt
March 16, 2011, 03:34 AM
You have a perfectly fine 100 yard range. Find out what range you want it zeroed for, find out how high it needs to be at 100 and make it hit that high. Zeroing on the front side of the trajectory is only for cases when you can't get the target out far enough to zero on the back side.

kwelz
March 16, 2011, 09:32 AM
Why would you want a 100 yard Zero?

Onmilo
March 16, 2011, 10:10 AM
Why would you want a 100 yard zero?
Some back up iron sights are regulated in 100 Meter graduations.
They are designed for engaging human sized targets at specific ranges and a 100 meter zero will allow the shooter to hit the intended target at ranges less than 100 meters with the sight set at 100 meters.
ACOG scopes are designed to be regulated at 100 meters as are other optic devices.

Close Quarter Combat shooting isn't precision shooting, leave that to the snipers.

Sometimes the other side gets so close you can engage them just by using the front sight as a reference.
He who fires first and scores hits wins.

Engaging targets that shoot back at 100 meters+ you have enough time to acquire a proper sight picture, usually.
Anything closer than that you are wasting time that can get you killed.

Since many if not most combatants now wear body armor taking a center mass aiming point not such a good idea.
At longer ranges with a well regulated rifle, a good marksman can make head shots, even with the targets shooting back.
At close range it is better to engage using only the front sight and placing it on the pelvic area.
A bullet in the groin will drop an adversary faster than three hits in the ceramic plate and they aren't near as likely to start shooting back at you.

kwelz
March 16, 2011, 10:13 AM
Umm.. Ok yeah... Sure. I will stick to stuff that actually works in the real world.

Tirod
March 16, 2011, 10:16 AM
Zero at the point blank range, it'll be within inches regardless of range out to your maximum.

Most medium game has an 18" square kill zone. Put the majority of the trajectory inside it for the caliber, gun, and ability you have. If it's an intermediate cartridge, it has about a 400 meter effective range, and so does the shooter. The top of the ballistic path centered on the target is about 2-3" high, out at 250-300 yards. Sight in at that distance that high over a 1" bull.

What you get is fast targeting, and no figuring holdover. Just acquire COM and press the trigger. The rise and fall of the bullet will be within 6 inches, it should be a hit. At longer distances hunting, hits count, not misses from calculating holdover and watching the game step off behind concealment.

Bambi's mother, or even an insurgent, doesn't always lolligag around in open terrain.You have to see them, get them in the sights/scope, which can take time, and then put the crosshairs accurately where you need to hit them.

The point blank range is quicker, effective, and works. Sighting in at that distance gives more practice at longer ranges, which is what a lot more hunters need. It's like the Army or the Olympics, train like you fight, and training is usually harder and longer so that the real thing is actually a bit easy.

kwelz
March 16, 2011, 10:22 AM
Tirod I see what you are saying but don't think I fully agree. While it is true that the trajectory will usually put it within 6 inches or so out to 200 yards, there are also times when more accuracy is needed.

We train using a 5.5 inch COM target and a 1 inch head target. Anything outside of that isn't acceptable. The general idea is Aim Small Miss Small. It is important to learn how high or low you need to aim at a given range. You never know what the situation you are going to be in may be. And if you ever need to shoot past something or someone it is important to know where you need to out the dot to hit a fairly small target.

benEzra
March 16, 2011, 11:09 AM
A 50-yard zero gives you a nice MPBR for a small target (far zero is around 200-220) and you don't have to hold over much for 300.

4thPointOfContact
March 16, 2011, 11:16 AM
I usually go for a 50-yard zero, since that's usually a marked yardage on most ranges.

But .... Truth to tell, from looking at the ballistic arcs for both 50 and 25, I'd much rather have something that split the difference. For my anticipated uses of a 5.56 I'd zero right around the 37-yard mark if I could.

CraigC
March 16, 2011, 11:41 AM
I know traditionally sighting in is done at 100 yds, but i can barely see the big black circle, let alone the bulls eye at that distance.
You don't need to see the bullseye, let alone hit it. Nor do you need to be shooting at a tiny little target to shoot tiny little groups. All you need is a target that you can consistently bracket your front sight against, shot after shot. I'd recommend a six o' clock hold on a 6"-8" square target for shooting at a hundred yards with a post front sight. Adjust your sights accordingly. I like for my shots to pile right on top of the front sight at my zero range. With a proper target and skilled shooter, there's no reason why you can't shoot near the rifle's potential at 100yds with the issue peep sights.

Sky
March 16, 2011, 12:15 PM
Yes the normal shooting range you anticipate. Open range where you can see for some distance or be seen then longer zero. Brush or woodlands not many 300 yard shots. My night scope I got on target at night at 27yards (started at 15). Then re-zeroed out to 125 yards which is about all I can see something on a pitch black night. Pigs and Jack rabbits at night are hit with acceptable results for me.

Art Eatman
March 16, 2011, 12:40 PM
I set up any centerfire to hit about two inches high at 100 yards. That's right at dead-on at 200, and roughly six inches low at 300. Plenty good for hunting, whether prairie dogs or deer.

Paper punching? I'd sight in for the distance I will be using.

Rmiller31
March 16, 2011, 01:06 PM
Someone at m4carbine.net has a target you can download to aid you in this. I'm on my phone at work or id dig up the link for you.

Andrew Wyatt
March 16, 2011, 01:18 PM
Why would you want a 100 yard Zero?


That's not what i was suggesting. I was suggesting you use your hundred yard range, and zero the weapon high at 100 so it is dead on at what ever range you want it to be dead on at.

benzy2
March 16, 2011, 01:30 PM
Again, we can go around and around about what the best battle zero is, but in truth, if this is a range only rifle it doesn't make much sense to worry about sighting in for a distance it won't be shot at.

To the OP, what are you shooting at and at what distance(s)?

Double Naught Spy
March 16, 2011, 05:45 PM
Why would you want a 100 yard Zero?
Because they are going to be shooting at that distance.

Umm.. Ok yeah... Sure. I will stick to stuff that actually works in the real world.
Lots of things work in the real world. The military may use various zero points.
http://www.armystudyguide.com/content/army_board_study_guide_topics/m16a2/zero-and-m16a2-rifle.shtml

It allows you to have a 50/200 zero and you can easily tell where you need to be at 25 as well. a strait 25 yard BZO is no where near as flexible.

That depends on whether you want shorter range flexibility or longer range flexibility.

And if you ever need to shoot past something or someone it is important to know where you need to out the dot to hit a fairly small target.

Tell me again because I am not clear on this and I don't think the OP will either. Just where is the dot on our iron sights?

I noticed most folks have the most problem inside of 25 yards or so, usually inside 2 or 3. While the sights may be just above the bottom window edge of a hummer, that doesn't mean the muzzle is. Armor stops rounds from leaving hummers as well.

Maverick223
March 16, 2011, 10:46 PM
That depends on whether you want shorter range flexibility or longer range flexibility.Exactly. I shoot more frequently at longer ranges (most often 300yds, though I am using optics) and sometime stretch it out to 400+, a 50/200yd sight in would be foolish for me, whereas a 30/300 is just about right (and keeps me within 5in. till about 350yds).

While the sights may be just above the bottom window edge of a hummer, that doesn't mean the muzzle is. Armor stops rounds from leaving hummers as well.Hehehe; can't say I haven't made this mistake in the past...can't say is was in a Hummer though. FWIW a round will leave a pic-a-nic table. ;) :uhoh:

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