25 yard zero?

Theres no doubt the close zero is handy, but I still dont see you not verifying the at the longer ranges to fine-tune them. Especially if youre shooting for precision.

I do use them to save time and ammo initially, but Ive always had to make some minor (and some not so minor) adjustments, both horizontal and vertical at the longer ranges to fine-tune the zero.

MEHavey said:

2.5" AR scope

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Lot different then irons.

243: how high is the center of that scope from the center of the bore, and I'll show how the 25yd/1.5" rule plays out.

Sold it in 2011.

25 yard zero isn't exactly a myth. It works to some degree based on rifle and caliber. 25 yard zero is the standard for dialing in M16/M4. I have done this enough times in A2 iron sights, red dots, ACOG (annoying at 25yard, easier at 175 known distance), and backup iron sights. The cards have changed over the years telling you exactly how to change the sight based on where you hit. From rotating knobs and posts to clicks on an optic. The ballistic science is the 5.56 arc at 25 yards is the same at 300 yards. The 25 yard zero has migrated to civilian world too. Most indoor ranges, even for rifles, are 25 yards to zero.

243winxb said:

Sold it in 2011.

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OK let' s play the game anyway.
ASSume a whopping 5" above the bore,... as opposed to baseline 1.5" for a scoped bolt action which we used to set 25yd POI at "zero" in Post#10 for the 30-06
Assume also the 5.56mm M885 @3,150fps

Baseline for 1.5" scope at 25yds is "Zero"
Since 5" scope already has bullet setting out 3.5" lower than baseline, set 25yd POI also to -3.5" lower than POA

Shoot:

I zero my AR's at 25 yards, then fire groups at 50, 100, and 200. With 16'-20" barrels, I'm still above the zero line at 200" My pistols will be under at 200, but not tragically. Most other calibers I start at 25, then bring it out to 50 or 100 and zero there.

I think people are arguing apples and oranges in this thread.

There's no one first zero that's absolutely correct for all combinations of rifle, caliber, barrel length, bullet weight, bullet type, cartridge load, ambient conditions, optic, etc.

That being said, being in the ballpark is close enough for most situations.

MEHavey said:

Assume also the 5.56mm M885 @3,150fps

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Barrel 14.5" on M16A1 carbine . 2700 fps with 55 gr fmj.

The barrel on the M16A1 was 20" It was 14.5" on the M4 carbine. Also, M855 tends to keyhole past 250 meters out of an A1. Ask me how I know.

wiscoaster said:

I think people are arguing apples and oranges in this thread.

There's no one first zero that's absolutely correct for all combinations of rifle, caliber, barrel length, bullet weight, bullet type, cartridge load, ambient conditions, optic, etc.

That being said, being in the ballpark is close enough for most situations.

Click to expand...

Yup!

"Battle"/"hunter" zero must be looked at differently than "precision rile" zero!

Battle/hunter zero can be broken down to +/- 4"'s due to common wound channels with this ammo. Knowing the front sight/reticle above bore center can be taken into consideration for understanding trajectory.

There are ballistic tables available for just about every cartridge/bullet available in my neighborhood.
In reviewing these tables you may notice that the difference in POA/POI from 25 yards to 200 plus yards is within 4 inches! Getting closer to 300 yards "ballistic coefficient" really becomes a factor. And a drop of 8 inches or more become evident.

Every fall I assist at our club/range with "hunter sight in"! I get to see just about every manner of cartridge, bullet combination! I don't recall any that were outside the 4 inches +/- mentioned above.

We usually start at 25 yards and verify at 200 yards. To get there involves several steps especially with new rifles and shooters. I use a level and torque driver to establish a good "base"! I have seen "rifle/scope" packages that could never work because the bases were incorrect!

Precision rifle POA/POI should the subject of an entirely thread!

Rifle "zero" is both a science and an art!

Smiles,

I shoot my AR weapons at 10 yards to obtain the 50-200 zero. So far it has checked out on all of my 223/556 AR15s. Is it the same as zeroing a rifle for precision work or hunting, nope but it flat works on an AR
Here is a link to the target
https://jerkingthetrigger.com/wp-content/uploads/2015/02/10-Yard-50-200-Zero-Target.pdf

The problem is everyone gets excited about a 25 meter zero because that is what the military has done since dinosaurs ruled the earth and yet they ASSUME ( come on military guys, tell them what "ASSUME" means) that means point of aim and Point of impact are the same at 25 meters.

That is not true. The 25 meter zero targets of whatever rifle had an easily seen and aimed at aiming point and a seperate "X" to show proper Point of impact at 25 meters to obtain a "Battle Sight Zero" (BSZ) for that particular weapon system and its sights.

So once I got a 25 meter zero on say my M14aiming at the Canadian Bull and I grouped might shots not where I was aiming but at an X a bit above my point of aim I could set my selevation drum to show 250 yards Battle sight and lock the drum back down. This allowed me to know that my rifle would hit where aimed at 250 yards AND I coul could be sure that if I aimed at a kneeling man target center of mass at any range from muzzle to 300 yards I would hit it between the bottom and top some place AND that if I adjusted my locked elevation drum to any range shown I would hit point of aim. It worked.

Some how folks got the idea that shooting a fill in the blank rifle with fill in the blank ammo at 25 meters so Point of Aim and Point of Impact match and are both one in the same was some sort of magic zero technique.

As Sporting Life might say " It ain't necessarily so."

I was once at a class where everyone whether it was a 10 inch AR "subgun" with Green tips or a GI M4 (14.5 inch) with green tip or a 16 inch "carbine' with some sort of 58 grain SP ammo, or a Mini-14 with Russian steel case 55 grain or a Full sized HBAR 15 shooting Lake City 193 Ball 55 grain ALL were zeroed to POA/POI match at 25 meters and all used effectively from 7 yards to 200 and rang the 200 yard 12 inch plate with regularity.

Now I will say that with most hunting rifles or military rifles that are zeroed at POA/POI at 25 meters that MOST ALL will allow you to get a hit on say a sheet of notebook paper at 100 meters Further than that and you might be wasting your time though. So zero at 25. Then zero at 100. Then check whatever charts you have and make adjustments to hit at whatever range you want to be your default setting zero.

It does not matter if you can shoot a sub MOA group if you do not know where it will be.

Learn your trajectory charts for your rifle and confirm your hold over or adjustments at various ranges.

Shoot.

A lot.

Now do I need to start tapping my clearing rod on your helmet to keep your attention and do this again?

(maybe I should just save this and cut and paste NEXT TIME)

-kBob

It is not a myth

Oh, OK, so it's a 26 yd zero, not 25. I'll have to back up. Or get a short-barreled rifle, I guess.

SWAG it. Close enough.

army_eod said:

SWAG it. Close enough.

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My usual approach to life, the universe and everything.