Tomorrow I am headed to the range to re-sight in my iron sighted ar-15, and my aimpoint sighted scar. I have decided I am going to use the 50/200 yard zero on both, but my question is, does it really work as good as it sounds on paper? The reading I have found sounds like it is a very good idea, but I would like to from those who use this zero. How far off will my poi be at 100 yards?

Thanks

At 100 yards?

About 1-2" high with a 50 yard zero.

It's not about faith, it's about physics.
Thankfully .223 is a pretty flat shooting round.

Can you guys explain the 50-200 sighting?  Not sure I understand.

Zeroing @ 50yds will put your POI just an inch or two low @ 200.
IOW, you can kill whatever you want by holding dead-on out to 200yds.

From what I've read you are able to zero at 50 yards and have your point of impact not be more than 2" off your point of aim out to about 240 yards or so. It's meant to be a battle zero, not for shooting x's all the time.

Posted the same info that was just posted by others.  

you sight in a 50yds and the bullet crosses ~ the same plane again at 200yds as it loses velocity and starts to fall



 

I have my ARs set for 50yrds........like it alot.  I figure they say most military engagements are at 100yrds or shorter.....god forbid I am ever in a SHTF scenerio   I wont be engaging anything past 200yrds....I would rather go another way or let them go by.  If I ever do need to defend myself or family it will more than likely be at 50yrds or closer.

I assume you found the RIBZ link :



http://www.ar15.com/forums/topic.html?b=3&f=18&t=328143



I did it to all my irons, works great. Just remember if you have stock apertures and have altered the elevation drum you have to change it when flipping to the large aperture.

No, I didn't see that. That looks interesting, and I may give that a try.

I'm a little confused, since I have a removable handle, do I still follow the procedure by having (6/3, -4 clicks) for the RIBZ 100 yard setting?

The maximum point blank range of a 55 grain .223 round is about 230 yards as I recall.   Meaning it will not rise or drop more than 3" getting to 230 yards when zeroed at 50 yards. Pretty flat shooting round.

I've had my carbine zeroed at 50 yards for several years and think for a battle/combat/patrol rifle zero it is the way to go.  I have an aimpoint Comp M with a 4moa dot.  I know that from 50 to 225 yards the bullet will hit where my dot is.  I'm quite comfortable with it and have not had any problems qualifying with my carbine each year.  I have also got several other officers using it as well.

Sarge

I use 50yd zero exclusively on my rifles, mainly because it works great and doesnt require much in the way of thinking to keep shots in the neutralize zone on targets.



For practical shooting I think it's the best choice, since a 2" difference will get you on the steel at anything from 25yds to 200yds and unlike a 25m zero you don't have to compensate downward for that 4" elevation change at the 100yd mark.



You do have to be aware that it will be shooting low in very close ranges (0-10yds) and plan for that if you are going for single shot 'A' zone hits or partially obscured targets. Luckily at the close ranges you can see the holes and verify where you're hitting. Other than that just put the punkin on the post and you're good to go.



The main thing is to get a consistent zero. You can start sandbagged at 25yds and get a very tight, consistent group exactly 2" under the bullseye, then move it out to 50 yds and verify it's right on. May require minor adjustment.

I've reset my A2 sights on my Bushy carbine to RIBZ. I keep it set one click up from 25-300 (for potential HD use) but rotate it down to 50-200 when shooting outdoors.

My old eyes suck! I have a hard enough time focusing on targets out beyond 200 yards with iron sights, nevermind precision target work.

But I can still shoot "minute of ribcage" and that should be good enough!

At 100 yards I do much better with irons, just the facts of life I guess.

Look at this ballistics chart and you'll see what they are talking about:



.
.

1+  also will be a inch or so low at 25 yards   edit

I think you mean low.

wrong will be an inch or so low.....

I'm wondering how much barrel length would matter in this equation, say 16" vs. 20" ?

This gives you an idea:










 

Look at this ballistics calculator

I recently competed in a 3 gun competition with shots to 400 yards.  My local range is only 100 yards.

Even if you don't have a chronograph, you can probably find rough velocity of factory ammo from a similar length barrel as your rifle as well as the BC of your bullet (such as the post above mine).

This is good stuff right here.  It also takes into account your sight height compared to the bore.  Best of all, "It's FREE".

I actually printed out my chart and took it with me to the match.  I was able to hit all of my long range steel.

Thanks to the member who posted this about a month or two ago!

thanks

or if you have a windows mobile powers device - cell phone, pda, etc take a look http://www.ar15.com/forums/topic.html?b=1&f=5&t=848823&page=1





 

excellent information

So if I do 50yd zero I'll be:

1-2" hi at 100yds
           &
1-2" low at 200yds?

Think about it thus: the optics are sitting above the bore.  If the optical axis is perfectly parallel to the bore axis, you'd never hit the cross hairs; the bullet will drop because of gravity.  So the optical axis and the bore axis are very slightly convergent to allow you to hit a point of aim.  The bullet is rising to meet the cross hairs, but eventually it will fall back to Earth because of gravity.  If your zero is 50 yds (bullet rises to meet the optical axis 50 yds from the muzzle), it will continue to rise a couple of inches, (@ about 100 yds) then fall to intersect the optical axis again at around 200 yards.

I hope that made sense.

Thanks for the replies. I'm gonna give this a try tomorrow.

Basically yes.



In the original IBZ mode, you are zeroing for 200yds.



Dead on zero at 50yds will be slightly low at 200 so depending on load etc, at 50yds POI should be slightly above POA by 3/8 to 1/2 inch or so to give a true 200yd zero.



 

Basically, no.  Also, the Santose Improved Battlesight Zero is a 50 yard / 200 meter zero.

Basically its designed so you can put the dot on the target, and hit that target from CQB (under 25YRDS) out to about 250 yards.


An Aimpoint with a 4MOA dot.....the dot will cover 4" of the target at 100yards, and 8" of the target at 200yards, and 12 at 300, and so on and so on.


Using the 50/200 yard zero allows you to put the dot of the sight on any target from CQB to 300yards, and the bullet will impact within the coverage of the dot.


So if you have a target at 75 yards...say a soda can....you can put the dot on the can and the bullet will hit the can. Go out to 250 yards, and put a coffee can out there, put the dot on the can, and the bullet will hit the coffee can.


With a 25 yard zero the bullet path rises TOO FAR above your sight line to be able to use the "put the dot on the target and squeeze the trigger" method. The bullet path will no longer fall in line with the line of sight of the optic. You would actually have to hold UNDER the target to hit it at say 125 yards.

The same goes with a 100 yard zero but its reversed. At 250 yards you would have to hold over your target to hit it.

So the 50/200 yard zero allows you to put the dot on the target at any range from CQB to 250 yards (might go out to 300 depending on your barrel and ammo selection) without having to use hold overs or hold unders.


This was always an issue during my time in the military because we always sighted in at 25 meters, and then went and qualified with targets going out to 300 meters. It messed a lot of people up having to use different aiming points on the targets depending on how far away they were. A 150 yard target you would have to nearly hold on the dirt just below the base of the target, but at 300 you could hold on the target. I am quite confident if the Army went to a 50 meter zero the average qualification score would improve quite a bit. Its much easier using the same hold point on the target no matter the distance (up to 250-300 yards) than having to use different hold points based on the range.


But if you have an optic like an ACOG which has a bullet drop compensator (BDC) you want to use the manufacturers method of zeroing because otherwise the BDC feature is not going to be accurate.

Hope this helps.

Only if you have the "half-clicks".  Both of my A3 handles had 6 click in between 3 and 4.

Meters/Yards






Give us your range report.




 

Aww someone already made one... I was about to pull my MS Paint one out haha

Okay, what about one more variable - The barrel height.  What happens when the shooter is lying prone and is shooting up to a 6' 50 yard target.  Won't the bullet travel too far upwards to hit at 200 yards??

I think the whole 50-200 thing only works when the target and the barrel height are the same - Correct???

So if one has A1 sights, the proper sight in would be the unmarked aperture (short range one) and sight in for bulls eye at 50 yards?

I am confused due to the Army sight in at 25 m with the long range sight up.

Thanks all,
Mortis...

The only difference there would be here is that, relative to the path of the bullet, gravity is now acting at a slight angle.  Instead of acting perpendicular to the path, it's acting down and slightly back.  

Assuming a max vertical difference in positions of say 50 inches, that's a difference of 1.6 degrees at 50 yards and 0.4 degrees at 200.  

Probably an unmeasurable difference, certainly not a practical one.

No, if you do a 50 yard zero, it will also be zeroed at 200 meters (219 yards), so at 200 yards (183 meters), it will still be a little high.  It will be low before 50 yards and after 200 meters (219 yards).

Excellent - Thanks for that answer - I won't worry about it then.

I guess most missed Molon's post and missed the 200 yard vs 200 meter reference.  There's a difference.   A 50 yard POI also happens to be the approx POI at 200 METERS not yards.  A 50 yard zero will leave the POI slightly high at 200 yards.  The Army uses a 25 meter zero while the Marines use a 36 Meter zero.

I can say what I see using my red dot(Comp M4S 2 moa dot).  I have it sighted in at 50 yards.  At 200 yards the POI is slightly high for me.  I think this method is generally for iron sights which are also lower to the bore.  When trying to apply to scopes the height above bore will change things.  Luckily many mounts can keep things closer to the bore.

For further explanation see this site:
Battlefield Sighting

A few highlighted remarks......

Would this method be recomended for a 10x scope?

If not, what method should I use?

Well, it works pretty well. The range I went to only goes to 80 yards, but at 80 yards my poi was a hair over an inch above my point of aim. This held true for both my aimpoint sighted scar, and my iron sighted ar-15. Since my carry handle has the "half clicks" I used (6/3, -4) for my 50 yard zero. Now that I have a good 50 yard zero I'm ready to go to another local range that 300 yards and see how well I can hit from 0-300 yards, and some in between ranges.

ETA: I used the small apeture the whole time, simply becuase I can shoot better with it.

In a SHFT scenario past 200 yards, I'll be shouldering one of my Mosins, preferably the 91/30!