If a .30/06 is sighted in for POA at 25 yards, will the POA at 100 yards be low or high ?
Sighting In
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POI will be high with iron sights at 100yd, even higher with a scope (around 2", depending on scope height).
So you would aim low at 100 yd if you are shooting at something small enough to matter. Shooting at a deer, most don't bother to aim low, just shoot at the center of the chest all the way out to about 250 yd.
So you would aim low at 100 yd if you are shooting at something small enough to matter. Shooting at a deer, most don't bother to aim low, just shoot at the center of the chest all the way out to about 250 yd.
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I sight my 06 to hit two inches high at 100 yards. That allows me to hold dead on at anything between 25 and 200 yards. 8 inches drop at 300.... here is a chart that shows what a 200 yard zero looks like for a 165 gr bullet
Accordingly a 25 yard zero would have you about 1.75" high at 100
Robert
Accordingly a 25 yard zero would have you about 1.75" high at 100
Robert
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I haven't tried that 25 yard rifle sight-in in a long time, but, as I recall, it's a might work / might not work thing. Far better to shoot at 100 yards to start. 25 or 50 would be okay just to get on paper.
I sight my 06 to hit two inches high at 100 yards. That allows me to hold dead on at anything between 25 and 200 yards. 8 inches drop at 300.... here is a chart that shows what a 200 yard zero looks like for a 165 gr bullet
Accordingly a 35 yard zero would have you about 1.75" high at 100
Robert
Yep. That's exactly how I zero mine in. Roughly 1.5"-2.0" high at 100 yds. gets me zero at 200 yds+
A 25 yard zero only tells you that you have a 25 yd. zero. Where the other zero is has a lot of variables like how high is the scope mounted, bullet speed and weight, etc. The way too find a 200 yd. or any other zero is too shoot at the distance you want too zero. Larry
The idea of a "25 yard" or "25 meter" zero started to be a (misunderstood) thing because the US Army started doing the *initial* zero for the M16A1, M16A2 and varius M4s at those distances on a 25 meter scaled silhouette target.
The military got there by doubling down by dumbing the process and the target. When the M14 and M16 were both in service, used the old "1000 inch" (25 meter) target. It has a aimpoint that looked like an inverted rear sight on a handgun. It provided a very precise aim point for a 6 o'clock hold and the target also had two Xs where the groups should be centered. The X above the point of aim was for the M14 and the X below it was for the M16 - using the short range aperture.
The M16A1 rear sight had two apertures: The short range aperture intended for a 250 meter zero and a second long range aperture (marked with an "L") for longer range shots past 300 meters.
Here's where people start to get it all wrong. With The M16A1 firing M193 ball, a 250 meter zero intersects the line of sight at 42 meters, not 25 meters. However, since the taller long range aperture is about three minutes higher than the short range aperture, zeroing to point of aim at 25 meters with the *long range* aperture (potentially) yielded a 375 meter zero with M193 ball ammo.
In other words, using the long range aperture allowed personnel to shoot to point of aim on the "1000 inch" target, and in turn eliminated the need to use the "1000 inch" target
Consequently, when the M14 was retired so was the "1000 inch" target. The US Army then started using a 25 meter scaled silhouette that appears to be the same size as a full-size silhouette at 250 meters. They could zero using the long range aperture and holding to point of aim at 25 meters and then flip back to the short range aperture to get the short range 250 meter zero (which let them shoot from 25m to 300m holding center of mass.
And of course the US Army dumbed it down even more by *not* explaining how it worked other than monkey see monkey do. For example recruits were taught one square on the new target was equal to one click in windage or elevation for zeroing purposes.
However, they never bothered to explain that one click equalled 1 MOA, what an MOA was, or that the long range sight raised the POA about 3 MOA.
With the M16A4 and M4, the carry handle sight now had 1/2 MOA adjustments on the M16A4, but they were greater on the M4 with it's shorter sight radius. The US Army however kept it dumbed down and just used different targets with different sized squares to get the initial zero. The US Army never got back up to speed on it until they adopted optics and were forced to start teaching recruits about angular measurements.
The second area where the whole 25 meter zero concept flies off the rails is the need for very precise zero and very small groups at 25 meters. The aiming circle in the silhouette target is 4 cm in diameter and the recruit was supposed to keep 5 out of 6 shots in 3 consecutive 3 shot groups inside the circle.
4cm at 25m is equivalent to 40cm at 250m. Skipping the math, that's 5.5 MOA edge to edge on that 4cm circle. So you could technically "zero" at 25m and still be 2 3/4 MOA off in both windage and in elevation. 2 3/4 MOA at 250m is almost 8" off your intended point of aim. Pretty poor for a zero.
For that reason, once a 25m zero was established, soldiers still needed to shoot at 250m to confirm that zero, where 2 or 3 MOA worth of clicks in windage or elevation might be needed to actually "zero".
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Unfortunately, the idea of a 25 yard or 25 meter zero is now very popular for folks who only have access to an indoor range, where 50 yards might be as long as it gets (and a shorter 25 yard range isn't uncommon).
That causes massive problems, especially if a "25 yard" range is actually only 23 or 24 yards. Unless the group is very precisely centered on the point of aim (and I'm talking bug hole groups) it is almost totally useless. Even then if your 25 yard range is really something like 23 yards, then your elevation will be off and you won't have the zero you think you have. Own a range finder? If not that 25 yard or 50 yard range is a real "trust me" proposition.
For example, when I was in the twin cities for about 9 months a couple years ago I shot at a range where they used a pile of ground rubber for the backstop. It was a "50 yard" range, and it may well have been 50 yards to the rear wall. However if you ran a target all the way back until the bottom rested on that sloped rubber berm, it was only 47 yards. 47 versus 50 makes a big difference if you want a precision zero.
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If you have access to a 100 yard range, by all means use it.
It's been traditional to zero centerfire hunting rifles so that they are 3" high at 100 yards. For the fairly common 150 gr SP in a 30-06 that 3" high at 100 yards lets the hunter hold dead on from 0 to 310 yards and not be more than +/-5 inches from the line of sight. Most hunters should not be shooting farther than 300 yards, and most hunters over estimate range so it all works out.
4" high at 100 yards actually works better as it also keeps the maximum mid range trajectory (about 165 yards) right at 5" and pushes the maximum point blank range (-5") out to about 335 yards. Plus the 8" bull on the 100 yard small bore rifle target is *" in diameter, so the shooter can hold dead center in the bull and then adjust so that the rounds impact at 12 o'clock on the bullseye, leaving the zero 4" high at 100 yards.
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That same 4" high at 100 yards works well for the 150 gr 30-30 as well, leaving it 4 1/4" high at about 140 yards and 5" low at 250 yards - a good zero for the .30-30. However, that is assuming you have a similar 1.7" height between the center of the scope and the center of the bore.
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There is a third problem with the 25 yard/meter zero - sight height makes a huge difference.
If you have a 30-30 with iron sights (the way God and John M Browning intended) the sight height is closer to .7" than it is to the 1.7" or so you'd have with a scope.
It doesn't have a huge effect if you are zeroing at 100 yards:
1.7" sight height/ zeroing at 100 yards:
25 yards = +0.4"
50 yards = +2.0"
100 yards = +4.0"
150 yards = +3.8"
200 yards = +1.2"
250 yards = -4.5"
253 Yards = -5.0"
.7" sight height / zeroing at 100 yards:
25 yards = +1.1"
50 yards = +2.5"
100 yards = +4.0"
150 yards = +3.3"
200 yards = 0.2"
243 yards = -5.0"
250 yards = -6.0"
However, if you decide that you can zero .4" high at 25 yards but then do it with a rifle with iron sights, it won't work so well as you end up about 50 yards short at 5" below the line of sight. The angle of departure is lower with the lower sight height and the same zero won't work when zeroing at short range as the change in angle is 4 times greater at 25 yards than it is at 100 yards:
0.7" sight height/ zeroing .4" high at 25 yards:
25 yards = +0.4"
50 yards = +1.1"
100 yards = +1.1"
150 yards = -1.0"
194 yards = -5.0"
200 yards = -5.6"
However it is way, way worse if you decide that you want to zero 1.1" high at 25 yards, like would with iron sights, but then use a scope. Here the angle of departure gets really screwed up and you'll be shooting about 9" higher than you think you will be at 250 yards.
1.7" sight height / zeroing 1.1" at 25 yards:
25 yards = +1.1"
50 yards = +3.5"
100 yards = +6.9"
150 yards = +8.2"
200 yards = +7.0"
250 yards = +2.7"
300 yards = -5.1"
The takeaway here is that the shorter the distance to the target you are actually shooting to "zero", the more critical sight height above the bore becomes, because it has an increasing effect on the angle of departure and any error in sight height will be greatly magnified.
The military got there by doubling down by dumbing the process and the target. When the M14 and M16 were both in service, used the old "1000 inch" (25 meter) target. It has a aimpoint that looked like an inverted rear sight on a handgun. It provided a very precise aim point for a 6 o'clock hold and the target also had two Xs where the groups should be centered. The X above the point of aim was for the M14 and the X below it was for the M16 - using the short range aperture.
The M16A1 rear sight had two apertures: The short range aperture intended for a 250 meter zero and a second long range aperture (marked with an "L") for longer range shots past 300 meters.
Here's where people start to get it all wrong. With The M16A1 firing M193 ball, a 250 meter zero intersects the line of sight at 42 meters, not 25 meters. However, since the taller long range aperture is about three minutes higher than the short range aperture, zeroing to point of aim at 25 meters with the *long range* aperture (potentially) yielded a 375 meter zero with M193 ball ammo.
In other words, using the long range aperture allowed personnel to shoot to point of aim on the "1000 inch" target, and in turn eliminated the need to use the "1000 inch" target
Consequently, when the M14 was retired so was the "1000 inch" target. The US Army then started using a 25 meter scaled silhouette that appears to be the same size as a full-size silhouette at 250 meters. They could zero using the long range aperture and holding to point of aim at 25 meters and then flip back to the short range aperture to get the short range 250 meter zero (which let them shoot from 25m to 300m holding center of mass.
And of course the US Army dumbed it down even more by *not* explaining how it worked other than monkey see monkey do. For example recruits were taught one square on the new target was equal to one click in windage or elevation for zeroing purposes.
However, they never bothered to explain that one click equalled 1 MOA, what an MOA was, or that the long range sight raised the POA about 3 MOA.
With the M16A4 and M4, the carry handle sight now had 1/2 MOA adjustments on the M16A4, but they were greater on the M4 with it's shorter sight radius. The US Army however kept it dumbed down and just used different targets with different sized squares to get the initial zero. The US Army never got back up to speed on it until they adopted optics and were forced to start teaching recruits about angular measurements.
The second area where the whole 25 meter zero concept flies off the rails is the need for very precise zero and very small groups at 25 meters. The aiming circle in the silhouette target is 4 cm in diameter and the recruit was supposed to keep 5 out of 6 shots in 3 consecutive 3 shot groups inside the circle.
4cm at 25m is equivalent to 40cm at 250m. Skipping the math, that's 5.5 MOA edge to edge on that 4cm circle. So you could technically "zero" at 25m and still be 2 3/4 MOA off in both windage and in elevation. 2 3/4 MOA at 250m is almost 8" off your intended point of aim. Pretty poor for a zero.
For that reason, once a 25m zero was established, soldiers still needed to shoot at 250m to confirm that zero, where 2 or 3 MOA worth of clicks in windage or elevation might be needed to actually "zero".
-----
Unfortunately, the idea of a 25 yard or 25 meter zero is now very popular for folks who only have access to an indoor range, where 50 yards might be as long as it gets (and a shorter 25 yard range isn't uncommon).
That causes massive problems, especially if a "25 yard" range is actually only 23 or 24 yards. Unless the group is very precisely centered on the point of aim (and I'm talking bug hole groups) it is almost totally useless. Even then if your 25 yard range is really something like 23 yards, then your elevation will be off and you won't have the zero you think you have. Own a range finder? If not that 25 yard or 50 yard range is a real "trust me" proposition.
For example, when I was in the twin cities for about 9 months a couple years ago I shot at a range where they used a pile of ground rubber for the backstop. It was a "50 yard" range, and it may well have been 50 yards to the rear wall. However if you ran a target all the way back until the bottom rested on that sloped rubber berm, it was only 47 yards. 47 versus 50 makes a big difference if you want a precision zero.
----
If you have access to a 100 yard range, by all means use it.
It's been traditional to zero centerfire hunting rifles so that they are 3" high at 100 yards. For the fairly common 150 gr SP in a 30-06 that 3" high at 100 yards lets the hunter hold dead on from 0 to 310 yards and not be more than +/-5 inches from the line of sight. Most hunters should not be shooting farther than 300 yards, and most hunters over estimate range so it all works out.
4" high at 100 yards actually works better as it also keeps the maximum mid range trajectory (about 165 yards) right at 5" and pushes the maximum point blank range (-5") out to about 335 yards. Plus the 8" bull on the 100 yard small bore rifle target is *" in diameter, so the shooter can hold dead center in the bull and then adjust so that the rounds impact at 12 o'clock on the bullseye, leaving the zero 4" high at 100 yards.
----
That same 4" high at 100 yards works well for the 150 gr 30-30 as well, leaving it 4 1/4" high at about 140 yards and 5" low at 250 yards - a good zero for the .30-30. However, that is assuming you have a similar 1.7" height between the center of the scope and the center of the bore.
----
There is a third problem with the 25 yard/meter zero - sight height makes a huge difference.
If you have a 30-30 with iron sights (the way God and John M Browning intended) the sight height is closer to .7" than it is to the 1.7" or so you'd have with a scope.
It doesn't have a huge effect if you are zeroing at 100 yards:
1.7" sight height/ zeroing at 100 yards:
25 yards = +0.4"
50 yards = +2.0"
100 yards = +4.0"
150 yards = +3.8"
200 yards = +1.2"
250 yards = -4.5"
253 Yards = -5.0"
.7" sight height / zeroing at 100 yards:
25 yards = +1.1"
50 yards = +2.5"
100 yards = +4.0"
150 yards = +3.3"
200 yards = 0.2"
243 yards = -5.0"
250 yards = -6.0"
However, if you decide that you can zero .4" high at 25 yards but then do it with a rifle with iron sights, it won't work so well as you end up about 50 yards short at 5" below the line of sight. The angle of departure is lower with the lower sight height and the same zero won't work when zeroing at short range as the change in angle is 4 times greater at 25 yards than it is at 100 yards:
0.7" sight height/ zeroing .4" high at 25 yards:
25 yards = +0.4"
50 yards = +1.1"
100 yards = +1.1"
150 yards = -1.0"
194 yards = -5.0"
200 yards = -5.6"
However it is way, way worse if you decide that you want to zero 1.1" high at 25 yards, like would with iron sights, but then use a scope. Here the angle of departure gets really screwed up and you'll be shooting about 9" higher than you think you will be at 250 yards.
1.7" sight height / zeroing 1.1" at 25 yards:
25 yards = +1.1"
50 yards = +3.5"
100 yards = +6.9"
150 yards = +8.2"
200 yards = +7.0"
250 yards = +2.7"
300 yards = -5.1"
The takeaway here is that the shorter the distance to the target you are actually shooting to "zero", the more critical sight height above the bore becomes, because it has an increasing effect on the angle of departure and any error in sight height will be greatly magnified.
For a "New" set up it is nice to see a hole at 25 yards , than to miss four times at a 100 yard target on the first try !!
When you are on paper.........
then you can move out to 100 yards so you can fine tune the rifle.
Lots of ways to sight in a rifle, after a years layoff or switching to new ammo but dropping a rifle or putting on a new scope can put you off paper and only you can decide which distance is best to see what "Old Bettie" is doing on the next trip out.
On one hunting trip I missed a deer trying for a neck shot and set up a paper plate at 50 yards.
My first three shots with the .270 rifle, had only one hole, barely on the plate !!
Things happen out in the field, when hunting.
Tight groups.
When you are on paper.........
then you can move out to 100 yards so you can fine tune the rifle.
Lots of ways to sight in a rifle, after a years layoff or switching to new ammo but dropping a rifle or putting on a new scope can put you off paper and only you can decide which distance is best to see what "Old Bettie" is doing on the next trip out.
On one hunting trip I missed a deer trying for a neck shot and set up a paper plate at 50 yards.
My first three shots with the .270 rifle, had only one hole, barely on the plate !!
Things happen out in the field, when hunting.
Tight groups.
Very good points.
With a bolt gun and the 8" small bore bullseye target, if have a rear bag and either a good front rest or a bipod, you can remove the bolt, look through the bore and adjust the bag and rest so that the bullseye stays centered in the center of the bore as you look straight through it. In effect, the hole at the muzzle needs to be centered in the rifling as you look through the bore and the bull needs to be centered in the hole.
Once the rifle is properly set on the bags to maintain the alignment, carefully look through the scope without touching or disturbing the rifle and carefully adjust the cross hairs (again without disturbing the rifle) so they are centered on the bull. Then look through the bore again to ensure the bull is still centered in the bore.
If you do it right the alignment is quite precise and you can usually get the first shot on paper at 100 yards. If not, then re-set and repeat at 25 yards.
The challenge is with rifle types where you cannot look directly through the bore. There, you'll have to use a collimator, or start at a range short enough to get a round on the target.
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Once you have a single round on the target, whether it is 10 yards 25 yards or 100 yards, you can reset the rifle on the bag and rest so that the cross hairs are on you original aimpoint and then carefully adjust the scope so that the cross hairs are on the hole in the target. (Basically, you adjust the scope to point where the bullet went.) If you are not at 100 yards already you can move the target there now.
Next, fire a 3 to 5 shot group to confirm the initial adjustment and a get a starting point for your adjustment to your desired zero (on POA at 100 yards, or 4" high at 100 yards, etc.), Then fire a group to confirm the zero.
Provided there is no lag or hysteresis in the scope adjustments, and provided the adjustments are accurate, you can reliably zero and confirm the in 4 shots, but 2 or 3 groups is more the norm.
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I've encountered the occasional hunter who will drag out a 20 round box of ammo and claim it's been all he has needed to take X number of deer for X number of years. If that number per year is less than 2, it's a massive red flag as it means he is not even bothering to confirm his zero, let alone how the rifle is grouping.
At a minimum I prefer to see hunters showing up and then shooting a 3 shot group that demonstrates they and the rifle are shooting accurately and that the rifle is actually zeroed where the shooter thinks it is zeroed. It's important to do this after the rifle has survived the tender mercies of the airline or UPS and in similar temperature and climate conditions where he plans to hunt.
I've never gotten the concept of dropping cash on a license, a guide, travel, etc and then not wanting to spend less than $10 to confirm a zero. Even for a local hunter where the only cost is the tag, going cheap still doesn't make sense. It's also still not ethical to run around shooting at game animals with a rifle that may no longer be zeroed.
vonn
US Veteran
Some good information here. One thing that I recommend is actual field cold bore shots at unknown ranges to see how your gun performs under hunting conditions. Bench zeros can be much different than hunting condition zeros for many reasons.
New scope mounted, new sights mounted, or old sights / scope simply out of adjustment for any reason are a good reason to place a target at 25yds or even 20yds and take a careful well aimed shot to see where the set-up is placing the shot.
Doing the same thing but at 100yds will usually result in a blank target and 'where'd that shot go'. Why continue to throw rounds down range and wonder where they are striking. Plus the walk to the 100yd berm and back can wait for later.
A rig that's throwing round(s) wide or high/low can be seen on a target just 20 to 25yrds away. They'll still cut the paper unless the set up is really bad for some reason.
You can dial the scope of sights quickly in to the POA with but a couple shots simply because you can see where it's hitting.
You are in no-man's land guessing where they are going off into the dirt and weeds at 100yds.
After zeroing at 25yrds,,now move out to 100yrds.
You will be on target, probably not the POA as at 25yrds but again no wasted ammo and time wondering where those shots are going.
Adjust the sights/scope to suit your needs and you are done.
I see people all the time go right out and place a target at 100yrds and then run through an entire box of ammo trying to site in with no luck at all.
Dependence on a 'Laser Bore Sited' set up is one of the things I see and hear all the time and they expect the rifle to lay 'em in the X right off the bat. That's a get you on paper thing just like any other bore sighting effort.
Nothing like live fire to show you where they will land.
Doing the same thing but at 100yds will usually result in a blank target and 'where'd that shot go'. Why continue to throw rounds down range and wonder where they are striking. Plus the walk to the 100yd berm and back can wait for later.
A rig that's throwing round(s) wide or high/low can be seen on a target just 20 to 25yrds away. They'll still cut the paper unless the set up is really bad for some reason.
You can dial the scope of sights quickly in to the POA with but a couple shots simply because you can see where it's hitting.
You are in no-man's land guessing where they are going off into the dirt and weeds at 100yds.
After zeroing at 25yrds,,now move out to 100yrds.
You will be on target, probably not the POA as at 25yrds but again no wasted ammo and time wondering where those shots are going.
Adjust the sights/scope to suit your needs and you are done.
I see people all the time go right out and place a target at 100yrds and then run through an entire box of ammo trying to site in with no luck at all.
Dependence on a 'Laser Bore Sited' set up is one of the things I see and hear all the time and they expect the rifle to lay 'em in the X right off the bat. That's a get you on paper thing just like any other bore sighting effort.
Nothing like live fire to show you where they will land.
