Zero question for AR15

[KM1]

I realize this is a sniper type forum....but I thought with the expertise here individuals here could help with my question on Zeroing. I am NEW at this so please bear with me if my question's seem ignorant.

I have been reading over the past two months about zeroing and proper zeroing. It seems that most pieces I read discuss a couple things. First, the purpose of the rifle...how it is expected to be used or might be used. Second, that each zeroing scheme has its place and purpose. Third, there is NO perfect zero, each is specific to the needs of the shooter. Fourth, regardless of the zero use, the number one factor will be the skill of the shooter. And...well...tons of other good pieces.

At any rate, I am looking to figure out what zero might be best for the following.

AR15 w/16" barrel....223Wylde
Eotec HWS EXPS GRN Optic
Troy Industries Iron Flip Up back up sights for co-witness (through 1/3 bottom of Eotech)
Green Laser - mounted under barrel

Ammo: Likely Speer Gold Dot LE Duty .223 Rem 62grn SP (or the like, for self defense with accuracy, suggestions welcome)

Purpose of the rifle: Mainly Self Defense, but also target shooting out to, say, 100+ yards. Would love to target shoot farther, but without a magnifier, or a scope, and the increase in deviations outside of the main purpose of the rifle forcing more holdover/holdunder I don't think that is likely.

I am looking to use a 50 yard zero or the 100 yard zero. My goal is to have the narrowest ribbon of bullet rise and drop from....25yds out to approx. 100 or 120yds or so. I am hoping to use the bottom line of the Eotech reticle for targets from 0 to, say 10yds or so....from there I would like to simply point and shoot (putting the 1moa dot in the center of the reticle on target and pull the trigger, no hold over or under).

Is it even possible to have a zero which gives you only a 2" deviation, 1" up or down from center, to 100 yards? Could anyone give me approximations of the 50 yard Zero bullet path deviation at 25yds, 75yds, 100yds, and 150yds...and where that second Zero MIGHT be (about 200+yds???)?

And the approximations of the 100 yard Zero bullet path deviation at 25yds, 50yds, 75yds, and 150yds? I believe, from what I've read that the 100yd zero would simply drop after about 110yds, requiring only a hold over beyond that point.

Ok...I know enough, I think, to write what I wrote above, based on reading only. BUT not enough to use the readily available calculators to find all of this. My expertise is with handguns...not rifles.

Thanks for any helpful info!!!

Best,

KM1

 

[NH4X]

With your sight system. ..........50 yds and call it good.

 

[KM1]

With your sight system. ..........50 yds and call it good.

Thanks!!!

Is it even possible to have a zero which gives you only a 2" deviation, 1" up or down from center, to 100 yards? Could anyone give me approximations of the 50 yard Zero deviation at 25yds, 75yds, 100yds, and 150yds...and where that second Zero MIGHT be (about 200+yds???)?

Based on my ammo choice and rifle....do you know the deviation of the bullet path based on above question?

 

[NH4X]

WAG...wild azz guess..50yd zero...100yds about 1.5 / 2 in high......200 yds close to dead on.....ymmv
Edit: Shoot paper at those yardages. .....then youll have your answer.

 

[Naaman]

OP, You seem to understand that the point of impact will be affected by the ammo you are shooting. Generally, faster moving bullets will travel farther before dropping (so, less drop at distance). My understanding is that with 62gr 855, the second zero is at 210 yards.

For self defense accuracy, a 50-yard zero is an excellent choice. The deviation, IIRC is about 1.5-2" high at 100 yards.

Maybe a 60- or 70-yard zero could get you to within that 1" up or down that you're looking for, but at indoor distances, your hold over will be even higher.

 

[raz175]

Use the Hornady Ballistic Calculator to get a fairly good estimate. Using your choice of Speer Gold Dot 62 gr and their advertised velocity of 3000 fps, I came up with this for a 100 yd zero. There is less than 2" of movement between 25 and 150 yds.

 

[MontanaMan]

For your night time reading enjoyment & to confuse you even further:

Zero Considerations

The Zen of the 100 Meter Zero

In both cases, remember that deviations in your velocity from the velocities they are using as nominal , will have some minor affect & get more pronounced as the range increases.

Enjoy.........................

MM

 

[KM1]

Use the Hornady Ballistic Calculator to get a fairly good estimate. Using your choice of Speer Gold Dot 62 gr and their advertised velocity of 3000 fps, I came up with this for a 100 yd zero. There is less than 2" of movement between 25 and 150 yds.

Thanks so much....that was VERY helpful.

Based on that chart....the 100 yard zero seems the way to go for me out to 110+ yds, knowing that beyond that I am going to assume some type of hold over out to 200yds and beyond. That chart shows me a maximum +/- of only 0.9 out to 150 yds. AND, actually, .07 to that .09 from 25yds to 150yds. Am I reading that correctly?

So...say...I used that line (hold) at the bottom of the Eotech reticle up to 25yds (supposed to be for 7yds)....then the 1moa dot as point and shoot out to 110+ yds (fastest).....I would be within that 1" expectation I am seeking at ALL those ranges. Simply point and shoot...YES???

However, the actual real live testing I have seen done (only on the internet, and mostly 64gr same bullet) on that bullet, as far as velocity goes, is around 2700 to 2800fps rather than the shown 3000fps in that chart. Wouldn't that change everything???

Man...this is A LOT more complicated than most probably realize. But very interesting!!!

 

[KM1]

For your night time reading enjoyment & to confuse you even further:

Zero Considerations

The Zen of the 100 Meter Zero

In both cases, remember that deviations in your velocity from the velocities they are using as nominal , will have some minor affect & get more pronounced as the range increases.

Enjoy.........................

MM

Thanks so much for your response....very helpful. I have actually seen and read both of those links you left. They are good and did help me....but you are right....the more you get into this...the more confusing and complicated this can get....depending on what one wants out of their ammo and firearm.

 

[raz175]

When you look at the trajectory column, anything with a minus sign is below your zero point (example minus .7 inches at 25 yds, minus 1.9 inches at 175 yds.). You will need to input your data (velocity, bullet BC, etc.) into the calculator to get the best output. The chart that I did was just a generic based on data about the ammo and bullet.

 

[Trigger Monkey]

So check this out, this should help visualize the 100 yard zero on a target instead of columns of numbers. I don't know the velocity or accuracy of your 62gr ammunition but the next best thing I have to pull data from is some Hornady Frontier 62gr Spire Point that I shot earlier this year. It clocked in at around 2971 fps from a 16" barrel and shot about 2.5 MOA. So take a look at the diagram...

From 5-150 yards you're basically inside the area of a softball (3.8" black circle). The dashed circles represent a 2.5 MOA group at the corresponding distance, now there will be shots outside of that but you can generally expect to hit within that area. Holding the same point of aim, 200 yards will be just under the "softball but still in the center of mass of that BC-Zone. Need to push out to 250, hold at the neck and let her eat, 300 yards...hold top of the head.

 

[KM1]

So check this out, this should help visualize the 100 yard zero on a target instead of columns of numbers. I don't know the velocity or accuracy of your 62gr ammunition but the next best thing I have to pull data from is some Hornady Frontier 62gr Spire Point that I shot earlier this year. It clocked in at around 2971 fps from a 16" barrel and shot about 2.5 MOA. So take a look at the diagram...

View attachment 7369614

From 5-150 yards you're basically inside the area of a softball (3.8" black circle). The dashed circles represent a 2.5 MOA group at the corresponding distance, now there will be shots outside of that but you can generally expect to hit within that area. Holding the same point of aim, 200 yards will be just under the "softball but still in the center of mass of that BC-Zone. Need to push out to 250, hold at the neck and let her eat, 300 yards...hold top of the head.

That's GREAT...thanks so much. so you are under 4" from 5yds to 150yds....which is damn good for self defense I would think. AND...if one uses the bottom line of the Eotech reticle for anything 25yds and under....pulling up POI even closer to POA at those close ranges you really don't have to worry about anything until you are pushing 200+yds. So it is, basically point and shoot from 0 to 150yds, with 100 yard zero...with the understanding you are using two different parts of your reticle depending on distance.

This is what makes me lean toward the 100 yard zero over the 50/200 yard zero for 0 to 150 yards self defense type use.....unless I am missing something. It seems based an all this discussion that it gives me the least amount of deviation at that 0 to 150yd distance...and still allow some level of precision shooting from say 75 to150yds with knowing some type of holdover past that.

Am I seeming to understand this better now???

 

[slothlacrosse]

I drank the 36 meter zero Kool-Aid. Seems to work well for M855 out to 300.

 

[acudaowner]

shucks I though it was a cooking forum for people who like guns . or bird watchers from across the country with all the scenic pics that are posted all the time .

 

[Molon]

AR-15 Zeros and Trajectories



The 100 yard zero with a .223/5.56mm AR-15 carbine is a unique trajectory in that the bullet just “kisses” the line of sight at 100 yards and rides along it for approximately 10 yards before dropping back down below the line of sight. (Technically, the bullet does travel above the line of sight, but by only 0.010”; a fraction of the diameter of the bullet itself.)

For all other zeroing schemes, there are going to be two points were the bullet crosses the line of sight; the near-zero and the far-zero. For the near-zero, the bullet will cross the line of sight while traveling upward from the muzzle toward the apogee or “maximum ordinate,” its highest point of travel. For the far-zero, the bullet will cross the line of sight while traveling downward from the maximum ordinate.

Now, when assigning a name to a particular zeroing scheme, it would be helpful if that name gave descriptive information about that particular zero; that is, the name should give us information about the trajectory and how it is unique and differs from other trajectories.

As a point of reference, the Santose Improved Battlesight Zero is often referred to as a 50/200 yard zero, however this is incorrect. It is actually a 50 yard/200 meter zeroing scheme; and this is only with a very few particular combinations of bullet weight, barrel length/muzzle velocity and height of sights above the bore. As an example, a 20” barreled AR-15 A2 firing 62 grain M855 will not match the 50 yard/200 meter IBZ. Neither will a 16" barreled RECCE firing 77 grain MK262, nor a 14.5” barreled M4 carbine firing the 70 grain 5.56mm Optimized "Brown Tip" load. The same concept applies when people refer to a 50/225 yard zero. Only a very few specific combinations of bullet weight, barrel length/muzzle velocity and height of sights above the bore will match that description.

What this is all leading up to is this; except for a very few specific combinations of bullet weight, barrel length/muzzle velocity and height of sights above the bore, a 50 yard zero is a different zero than a 200 yard zero. For a 200 yard zero, we know that this trajectory will produce a far-zero in which the bullet will cross the line of sight at 200 yards in its downward travel from the maximum ordinate. (It is physically impossible to produce a 200 yard near-zero with any of the commonly available loads and barrels lengths used in .223/5.56mm AR-15s.) Other than for a very few specific combinations of bullet weight, barrel length/muzzle velocity and height of sights above the bore, the near-zero of the 200 yard zero will not be at 50 yards.


Conversely, a 50 yard zero tells us that this trajectory will have a near-zero in which the bullet crosses the line of sight at a distance of 50 yards in its upward travel to the maximum ordinate. For those who think that a zeroing scheme must be named after its far-zero, it is physically impossible to produce a far-zero of 50 yards with any of the commonly used loads and barrel lengths in .223/5.56mm AR-15s. The 50 yard zero can only be the near-zero.

Here are a couple of illustrations to aid in understanding some of the concepts described above. Lets start with the 100 yard zero as a reference point. As described above, with a 100 yard zero, the bullet’s trajectory just “kisses” the line of sight at 100 yards. Now, let’s increase the elevation setting of the sights/scope. As this is done, the near-zero can only move closer and closer to the muzzle. Concomitantly, the far-zero moves farther and farther away from the muzzle.

For the next illustration, we’ll start with the 100 yard zero again, only this time let’s decrease the elevation setting of the sights/scope. As this is done, the bullet’s trajectory can only fall away from the line of sight. The bullet will never cross the line of sight again; no zero at all.

Other than for a very few specific combinations of bullet weight, barrel length/muzzle velocity and height of sights above the bore, the far-zero of the 50 yard zero will not be at 200 yards; and for all practical purposes it matters not one bit. Whether the bullet crosses the line of sight for the second time (far-zero) at 189 yards, 200 yards, 215 yards or 225 yards will not make the slightest bit of difference in the practical application of the AR-15 as a defensive weapon. In each case we will be holding the same POA (beyond CQB distances) and know that we will be hitting within approximately 2 inches above or below that POA out to 200 yards (or farther depending upon barrel length and load.) You should have an idea what your actual far-zero is when using a 50 yard zero and confirm such at distance when possible, but again it’s most likely not going to be a 200 yard far-zero and again it does not need to be.

Choose your zeroing scheme based on the pertinent facts; not nonsense about “shooting through a cone.” When shooting at human targets, in the grand scheme of things there isn’t going to be any practical difference between a point of impact that has a negative deviation from the point of aim, (e.g. the bullet strikes 1.5” below the point of aim) and a point of impact that has an equal positive deviation from the point of aim (e.g. the bullet strikes 1.5” above the point of aim.) In other words, the absolute value of the point of impact from the point of aim (how far the point of impact deviates from the point of aim, regardless of whether it is a positive or negative deviation) is what we need to be concerned about. Therefore, one of the main points to consider when choosing a battle-sight-zero is this: What zeroing scheme produces the smallest absolute values for the deviations of the points of impact from the point of aim, over the distance that we reasonably expect to engage a human target in our intended usage?

The chart below illustrates the above concept. The chart compares the absolute values of the deviations of the points of impact from the point of aim (0.0 inches on the graph being the point of aim/line of sight) for a 50-yard-zero and a 100-yard-zero, using Hornady 5.56 TAP T2 ammunition.

As you can see in the graph above, from the muzzle (0 yards) to approximately 62 yards, the 50-yard-zero has a slight advantage over the 100-yard-zero. Between the distances of 62 yards and 165 yards, the 100-yard-zero has the advantage. From the distance of 165 yards out to the 250 yards shown in the graph, the 50-yard-zero has a distinct advantage over the 100-yard-zero. Choose your zeroing scheme based on the pertinent facts.



Some reference material. Except where noted, all barrel lengths are 20 inches

Courtesy of zrxc77



.

.

.


M855 25 yard zero

M855 25 meter zero

M855 36 yard vs 100 yard zero

M855

M855 and M193 25 meter zero

M855 and M193 50 yard zero from 16” barrel

M193 25 meter, 50 yard and 100 yard zeros from 16" barrel

100 yard zero

25 meter vs 50 yard zero, M855 from 16” barrel

25 meter vs 50 meter zero , M193 from 16" barrel

M855 300 meter zero

M855 200 meter vs 300 meter zeros

M855 36 yard vs 50 yard zeros

….

 

[Molon]

RIBZ

RevisedImproved Battlesight Zero



The standard A2 rear sights on an AR-15/M16A2 were designed with elevation settings for 300 to 800 meters. The Santose Improved Battlesight Zero allows for an elevation setting of 50 yards/200 meters for one of the most all-around useful trajectories obtainable with the 5.56mm/223 Remington cartridge when fired from an AR-15.


Neither of the above sighting schemes allow for an elevation setting giving you point of aim equals point of impact at 100 yards. Since 100 yard shooting ranges are some of the most commonly found ranges in the United States and some agencies are promoting the use of a 100 yard zero, it would be useful to have such a setting on our AR-15s. This can be achieved quite easily with nothing more than a 1/16” allen wrench. It’s really just a matter of taking the Improved Battlesight Zero one step further.


There is a witness hole on the A2 rear sight base that gives you access to the index screw that you will need to loosen with the 1/16” allen wrench to make the necessary alteration to the elevation drum. The witness hole lines up with the index screw only when the elevation drum is set to 8/3. Set your elevation drum on the 8/3 setting and turn the screw counter-clockwise 3 to 4 complete turns. You don’t want to remove the screw. You want to loosen it enough to allow the elevation index wheel (the top part of the elevation drum with the numbers on it) and the elevation knob (the bottom part of the elevation drum) to separate and be able to move independently of each other.

Once you have loosened the index screw, use one hand to hold the allen wrench in place on the screw and with your other hand turn the elevation knob (the bottom part of the elevation drum) 4 clicks clockwise.* You should see the rear sight base moving up while you do this. The elevation index wheel should not move while you are doing this. (We really only need to turn the elevation knob 3 clicks clockwise, but by turning it 4 clicks we get a “buffer zone” that keeps the rear sight base from coming into contact with the lower receiver when the sight is moved to the lowest used setting. This gives you a more consistently repeatable sight setting.)

Now that you have moved the elevation knob 4 clicks clockwise, taking care to make sure the elevation index wheel has not moved, firmly tighten the index screw. Starting with the elevation drum at the 8/3 setting, you should easily be able to turn the drum counter-clockwise 3 clicks and see the rear sight base moving down. (You should be able to turn the elevation drum one more click counter-clockwise for our “buffer zone.”) You are now ready to head to the shooting range.


As I mentioned earlier, this sighting scheme is really just taking the Improved Battlesight Zero one step further. Starting with the elevation drum at the 8/3 setting, turn the elevation drum counter-clockwise 3 clicks (8/3, -3). This is your 100 yard point of aim equals point of impact setting. From a distance of 100 yards, zero the rifle with the rear sight at this setting (using the small sight aperture). Do not change this rear sight elevation setting while zeroing. Use the front sight post only to make changes in elevation while zeroing.


The beauty of the RIBZ sighting scheme is that once you have zeroed the rifle with this method, you will have your 100 yard zero setting and the other settings of the elevation drum remain intact (within the limits of the coarse adjustments of the A2 sights). If you want to use the Improved Battlesight Zero, simply set the elevation drum to 8/3, -2 and you're good to go. To use the standard military 300 meter setting, just set the elevation drum to 8/3. You can also start the zeroing process by obtaining the Santose Improved Battlesight Zero at a distance of 50 yards with the rear sight on the 8/3, -2 setting. Obviously, slight variations will be encountered depending on the ammunition used and the actual amount of movement with each click of the various sights. The results will certainly be close enough “for government work.”


When using this sighting method, you may find that once you have set your 100 yard zero, the top of the base of the front sight post is now slightly above the top of the well in the front sight base. If this happens, the “0.040” taller” front sight post from Bushmaster provides a quick and inexpensive fix.

100 yard zero (8/3, -3)

Improved Battlesight Zero (8/3, -2)

Standard 300 meter zero (8/3)

All click references should be doubled when using detachable carry handle sights.

IBZ (6/3, -4)

While the Revised Improved Battlesight Zero is certainly not perfect, here is an example of how well it does work at the distances typically encountered at the public KD ranges in my state. I zeroed my 20” Colt with A2 sights at 100 yards as described in this thread. Here is a pic of a 10-shot group from 100 yards.





100 yards, (8/3, -3)

Next, I packed up my gear and headed to the 50 yard line. By simply coming up one click on the elevation wheel (8/3, -2), I was in the 10-ring at 50 yards.



50 yards, (8/3, -2)

Lastly, I moved down to the 25 yard line. With this sighting scheme, setting the elevation wheel to (8/3, +3) gives me the necessary elevation for 25 yards. (Again, due to the course adjustment of the AR-15 sights and manufacturing tolerances none of these settings are perfect.) In fact, if you don't have access to a 100 yard range or you just want to “get on paper” before heading to the 100 yard range to refine the zero, you can zero at 25 yards using this setting.



25 yards, (8/3, +3)

….

 

[Molon]

Federal 62 Grain Fusion vs Federal 62 Grain Fusion MSR vs Speer LE 62 Grain Gold Dot

The muzzle velocities shown in the tables below were obtained back-to-back during the same chronograph session using recent lots of all three of the Fusion/Gold Dot loads chrongographed.

Atmospheric Conditions

Temperature: 73 degrees F (plus or minus one degree)
Barometric Pressure: 29.68 inches of Hg
Humidity: 62%
Altitude: 950 feet above sea level



Muzzle velocities from a 20” Colt M16A2 barrel with a NATO chamber, chrome lining and a 1:7” twist.

Muzzle velocities from a 14.5 Noveske N4 light barrel with a NATO chamber, chrome lining and a 1:7’ twist.

10-shot groups were fired from one of my precision AR-15s with a Lothar-Walther barrel with a 223 Wylde chamber and a 1:8” twist. The groups were fired from the bench at a distance of 100 yards with the same sight settings on the scope for each of the three groups.

….

 

[Darkside-Six]

Here is a good example of your combat effective zone with 3 different zeros so you can see what you’re getting. For what you want, 50 y is probably the next option.

 

[KM1]

three . . .

Hi Molon,

I have read much of what you have posted in my search prior to my asking my questions above. ALL was very informative. In fact, all here have given great thoughts.

I want to look at what you have posted here and then may ask another question. Crazy....no one outside of firearms would EVER realize how complicated this can be with trajectories, barrel length, load, bullet weight, optics, purpose, etc., etc. Much more goes into this than the vast majority realize....unless one is into it. Me, just learning. My handgun knowledge helps....but this is a whole different ball game.

Thanks Molon....might get back to you once I read what you have here.

 

[Rerun7]

All the data you need is above.

I would also just say don’t over think it. With any of these schemes if you don’t practice with it then you won’t be proficient with it.

I use the 100 yard personally. For me, it’s easy to remember to start compensating inside of 50 yards or beyond 100 yards.

 

[KM1]

RIBZ

RevisedImproved Battlesight Zero



The standard A2 rear sights on an AR-15/M16A2 were designed with elevation settings for 300 to 800 meters. The Santose Improved Battlesight Zero allows for an elevation setting of 50 yards/200 meters for one of the most all-around useful trajectories obtainable with the 5.56mm/223 Remington cartridge when fired from an AR-15.


Neither of the above sighting schemes allow for an elevation setting giving you point of aim equals point of impact at 100 yards. Since 100 yard shooting ranges are some of the most commonly found ranges in the United States and some agencies are promoting the use of a 100 yard zero, it would be useful to have such a setting on our AR-15s. This can be achieved quite easily with nothing more than a 1/16” allen wrench. It’s really just a matter of taking the Improved Battlesight Zero one step further.


There is a witness hole on the A2 rear sight base that gives you access to the index screw that you will need to loosen with the 1/16” allen wrench to make the necessary alteration to the elevation drum. The witness hole lines up with the index screw only when the elevation drum is set to 8/3. Set your elevation drum on the 8/3 setting and turn the screw counter-clockwise 3 to 4 complete turns. You don’t want to remove the screw. You want to loosen it enough to allow the elevation index wheel (the top part of the elevation drum with the numbers on it) and the elevation knob (the bottom part of the elevation drum) to separate and be able to move independently of each other.

Once you have loosened the index screw, use one hand to hold the allen wrench in place on the screw and with your other hand turn the elevation knob (the bottom part of the elevation drum) 4 clicks clockwise.* You should see the rear sight base moving up while you do this. The elevation index wheel should not move while you are doing this. (We really only need to turn the elevation knob 3 clicks clockwise, but by turning it 4 clicks we get a “buffer zone” that keeps the rear sight base from coming into contact with the lower receiver when the sight is moved to the lowest used setting. This gives you a more consistently repeatable sight setting.)

Now that you have moved the elevation knob 4 clicks clockwise, taking care to make sure the elevation index wheel has not moved, firmly tighten the index screw. Starting with the elevation drum at the 8/3 setting, you should easily be able to turn the drum counter-clockwise 3 clicks and see the rear sight base moving down. (You should be able to turn the elevation drum one more click counter-clockwise for our “buffer zone.”) You are now ready to head to the shooting range.


As I mentioned earlier, this sighting scheme is really just taking the Improved Battlesight Zero one step further. Starting with the elevation drum at the 8/3 setting, turn the elevation drum counter-clockwise 3 clicks (8/3, -3). This is your 100 yard point of aim equals point of impact setting. From a distance of 100 yards, zero the rifle with the rear sight at this setting (using the small sight aperture). Do not change this rear sight elevation setting while zeroing. Use the front sight post only to make changes in elevation while zeroing.


The beauty of the RIBZ sighting scheme is that once you have zeroed the rifle with this method, you will have your 100 yard zero setting and the other settings of the elevation drum remain intact (within the limits of the coarse adjustments of the A2 sights). If you want to use the Improved Battlesight Zero, simply set the elevation drum to 8/3, -2 and you're good to go. To use the standard military 300 meter setting, just set the elevation drum to 8/3. You can also start the zeroing process by obtaining the Santose Improved Battlesight Zero at a distance of 50 yards with the rear sight on the 8/3, -2 setting. Obviously, slight variations will be encountered depending on the ammunition used and the actual amount of movement with each click of the various sights. The results will certainly be close enough “for government work.”


When using this sighting method, you may find that once you have set your 100 yard zero, the top of the base of the front sight post is now slightly above the top of the well in the front sight base. If this happens, the “0.040” taller” front sight post from Bushmaster provides a quick and inexpensive fix.

100 yard zero (8/3, -3)

Improved Battlesight Zero (8/3, -2)

Standard 300 meter zero (8/3)

All click references should be doubled when using detachable carry handle sights.

IBZ (6/3, -4)

While the Revised Improved Battlesight Zero is certainly not perfect, here is an example of how well it does work at the distances typically encountered at the public KD ranges in my state. I zeroed my 20” Colt with A2 sights at 100 yards as described in this thread. Here is a pic of a 10-shot group from 100 yards.





100 yards, (8/3, -3)

Next, I packed up my gear and headed to the 50 yard line. By simply coming up one click on the elevation wheel (8/3, -2), I was in the 10-ring at 50 yards.



50 yards, (8/3, -2)

Lastly, I moved down to the 25 yard line. With this sighting scheme, setting the elevation wheel to (8/3, +3) gives me the necessary elevation for 25 yards. (Again, due to the course adjustment of the AR-15 sights and manufacturing tolerances none of these settings are perfect.) In fact, if you don't have access to a 100 yard range or you just want to “get on paper” before heading to the 100 yard range to refine the zero, you can zero at 25 yards using this setting.



25 yards, (8/3, +3)

….

The first response you posted I have read already....but where I read it, it did not have the images....those were very HELPFULL!!! The second was new for me....and a very good read as well.

Ok...based on what I am looking for, and trying to digest all you have here, and combining it to what I know (or think I know) already, here is what I am interpreting. And A LOT of this is based on this paragraph in your first post....

." As you can see in the graph above, from the muzzle (0 yards) to approximately 62 yards, the 50-yard-zero has a slight advantage over the 100-yard-zero. Between the distances of 62 yards and 165 yards, the 100-yard-zero has the advantage."

In order to accomplish my purpose of best practice and smallest bullet deviation from 0 to about 110yds (for self defense purposes, mainly). I am looking at doing the following (and any further ideas or suggestions are welcomed).

1. Setting rifle up for 100 yard zero with all sighting options (Eotech, Iron sights, & Lazer)
2. 0 to about 25+ yds....using bottom circle hash mark in reticle as my hold point. Based on what I am interpreting...this will raise my POI closer to my POA (marginalizing mechanical offset) at this distance.
3. Beyond 25+ yards I will use the 1moa dot for POA accepting the approximate -1" or less drop at 50, which will decrease all the way out to my zero at 100yds. Between 25yds and 50 yds....I can play with which will give me the least amount of bullet deviation from my POA between that bottom dash of the reticle or that 1moa dot...and go with whichever is best in that distance. May be negligible.
4. Anything out past, say150yds or so will need some amount of holdover.

The only other option practical for my use would be:
1. Setting rifle up for the 50yd zero with all sighting options
2. Same using lower dash of reticle 0 - 25 yds
3. Beyond 25 yards use 1moa dot of reticle....only this will give me less deviation of bullet from POA because of the 50 yard zero.
4. Accept the approx. 2" deviation over POA at 100 yds.
5. Anything out past 200 yds will need some holdover.

It just seems I can more easily, quickly accommodate the smaller bullet travel deviations between 0 and 25yds with that low reticle dash, accept the deviations beyond that since it might be less than 1", than have to deal with the larger bullet deviations that occur beyond 50yds with that 50 yd zero.

Does that make any sense????

Once I get it zeroed at 100yds I will check POA & POI at 7yds, 25yds, 50yds, 100yds using the first procedure, make adjustments if needed, and see where I am at...if I am comfortable with what I find using my rifle and the ammunition I will be using...I would be good to go. Will be interesting. Maybe I'll get lucky and at 7ds POA & POI will be close to dead on at 7yds using that lower slash....and deviations beyond that won't be more than 1"....but we will see. Won't know any of this for sure until I actually go out, zero, and shoot at these distances.

 

[MontanaMan]

Therefore, one of the main points to consider when choosing a battle-sight-zero is this: What zeroing scheme produces the smallest absolute values for the deviations of the points of impact from the point of aim, over the distance that we reasonably expect to engage a human target in our intended usage?

Quite a post............you must be bored today.

The above points out the nut of the situation, taken in conjunction with what kind of optic is used, ie., "short range" or long range.

Short range, ie, red dot, etc, gets a 100 yard zero.

"Long range" depending on the exact gun & optic will get a 200-250 yard zero & dial the scope for anything over 300 yards.

Just my way KISS....................

MM

 

[KM1]

Quite a post............you must be bored today.

The above points out the nut of the situation, taken in conjunction with what kind of optic is used, ie., "short range" or long range.

Short range, ie, red dot, etc, gets a 100 yard zero.

"Long range" depending on the exact gun & optic will get a 200-250 yard zero & dial the scope for anything over 300 yards.

Just my way KISS....................

MM

Yes...I thought that too...that statement is what I am looking at as a guide as well. Thus, I am looking for which zero will produce the smallest absolute values for the deviations of the points of impact from the point of aim, over the distance that we reasonably expect to engage a human target in our intended usage

Distance: 0 - 110+ yds
Sights: Using Eotech lower slash in reticle to 25+yds or so / 1moa dot used 25+yds, or so, to 110+yds
Unless I am not interpreting what I am reading correctly, using that above statement as the "guide"...the 100 yard zero accomplishes this best....yes???

 

[Trigger Monkey]

Yes, zero at 100 yards, this will accomplish what you want to do with the rifle based on what you've written so far.

Sights: Using Eotech lower slash in reticle to 25+yds or so / 1moa dot used 25+yds, or so, to 110+yds

Don't do this, zero at 100 and learn to use the 1 MOA dot from 0-110-ish yards. The only time you'd really use that lower slash is in the 5-10 yard range if you wanted to put rounds in the credit card (T-BOX or A-Zone in the head portion of an IPSC target). As you get past that the radius of the reticle begins to exceed the distance the bullet would impact below your point of aim and you'd be sending shots high. At 25 yards for example the radius of the reticle is about 8 inches, the bullets impact about 1.5" low at the distance with a 100 yard zero, see what I mean?

Keep it simple.

 

[KM1]

Ok...that makes sense. I think that lower slash is for up to 7yds if I read the Eotech info I found correctly.

To clarify and finalize your last thought. Zero at 100yds, use the lower slash only for close precision shots...no farther than 10yds. Use the 1moa dot for everything past 10yds to 110ish yds, actually 0 to 110ish yds, anything past 110 I'd likely need some type of holdover. SIMPLE!!!

Correct?

 

[KM1]

Ok...that makes sense. I think that lower slash is for up to 7yds if I read the Eotech info I found correctly.

To clarify and finalize your last thought. Zero at 100yds, use the lower slash only for very close precision shots...no more than 10yds. Use the 1moa dot for everything past 10yds to 110ish yds, actually 0 to 110ish, anything past that I'd likely need some type of holdover.

Correct?

 

[Trigger Monkey]

You probably won't have to start holding over until after about 150 yards, remember my softball analogy from above?

 

[KM1]

You probably won't have to start holding over until after about 150 yards, remember my softball analogy from above?

Yep....perfect....or at least as close as I can get to 110ish. Thanks so much.

Best,

KM1

 

[scout0610]

Thanks so much....that was VERY helpful.

Based on that chart....the 100 yard zero seems the way to go for me out to 110+ yds, knowing that beyond that I am going to assume some type of hold over out to 200yds and beyond. That chart shows me a maximum +/- of only 0.9 out to 150 yds. AND, actually, .07 to that .09 from 25yds to 150yds. Am I reading that correctly?

So...say...I used that line (hold) at the bottom of the Eotech reticle up to 25yds (supposed to be for 7yds)....then the 1moa dot as point and shoot out to 110+ yds (fastest).....I would be within that 1" expectation I am seeking at ALL those ranges. Simply point and shoot...YES???

However, the actual real live testing I have seen done (only on the internet, and mostly 64gr same bullet) on that bullet, as far as velocity goes, is around 2700 to 2800fps rather than the shown 3000fps in that chart. Wouldn't that change everything???

Man...this is A LOT more complicated than most probably realize. But very interesting!!!

Don’t know if anyone mentioned this, but you’re going to have a significantly lower muzzle velocity than what they say on the box of ammo depending on the length of your barrel, because they generally test with longer length test barrels than your carbine will have... like someone else mentioned, get your zero, then put paper targets up at the ranges in question and shoot a couple of groups using the aiming points you’re talking about using for those distances. That will confirm to you that you’re good to go, as well as make you more confident about using those points of aim on the reticle. Have fun.

 

[KM1]

Don’t know if anyone mentioned this, but you’re going to have a significantly lower muzzle velocity than what they say on the box of ammo depending on the length of your barrel, because they generally test with longer length test barrels than your carbine will have... like someone else mentioned, get your zero, then put paper targets up at the ranges in question and shoot a couple of groups using the aiming points you’re talking about using for those distances. That will confirm to you that you’re good to go, as well as make you more confident about using those points of aim on the reticle. Have fun.

Yep....that is the plan. I am guessing out of a 16" barrel velocity will be around 2700fps or so. That is what I am gathering. But yes, I'll have to shoot those distances to know.

Plus, my range is only 25yds....so I am going to have to use a 25yd adjusted for 100 yd zero. Not perfect....and checking it at 50 and 100, yes......but will have to wait until I can find those distances to check it.

 

[scout0610]

Yep....that is the plan. I am guessing out of a 16" barrel velocity will be around 2700fps or so. That is what I am gathering. But yes, I'll have to shoot those distances to know.

Plus, my range is only 25yds....so I am going to have to use a 25yd adjusted for 100 yd zero. Not perfect....and checking it at 50 and 100 yes will have to wait until I can find those distances to check it.

Well at least you can confirm within 25 yards...that will tell you a lot about engaging at the most common self defense ranges anyway. If you do paper at say 7,16,25 yards, you can measure groups From point of aim to point of impact and adjust the ballistic engine to actual data and find your avg. muzzle velocity, then use that to calculate closer to expected impacts with the ballistic engine beyond those you have access to...essentially just a way to figure out what’s happening with your rifle with the resources you have available. When all is said and done, it comes down to how much standard deviation you’re willing to accept. The procedure I just suggested is definitely not something you need to do, as I’m sure the difference would be negligible. Just thought I’d give you something interesting to do while you play with your new toy...

 

[KM1]

Well at least you can confirm within 25 yards...that will tell you a lot about engaging at the most common self defense ranges anyway. If you do paper at say 7,16,25 yards, you can measure groups From point of aim to point of impact and adjust the ballistic engine to actual data and find your avg. muzzle velocity, then use that to calculate closer to expected impacts with the ballistic engine beyond those you have access to...essentially just a way to figure out what’s happening with your rifle with the resources you have available. When all is said and done, it comes down to how much standard deviation you’re willing to accept. The procedure I just suggested is definitely not something you need to do, as I’m sure the difference would be negligible. Just thought I’d give you something interesting to do while you play with your new toy...

Yes.

After zeroing using that adjusted 25yd target for 100yd Zero....and then checking my POA/POI at the various ranges you mention....I may try that bottom slash of the reticle at that 7 yard range to see where POA/POI actually is on paper, using that for precision T-BOX shooting. Everything else, like Trigger Monkey said, use the 1moa dot on paper and see where everything comes out to at my 25 yds range.

This KNOWING I will be low on all of these, question is how much (should be minimal, about 1" or less, hopefully), with the exception of that 7yd shot with the lower slash. It will be interesting to see how close I am with POA/POI with that at 7yds.

AND, I assume through practice, and after I check my actual zero at 100yds, I will get better at KNOWING where that 1moa dot puts my shots on paper at various distances with the ammo I use. Thus, can make any immediate adjustments within that 110ish yard range. That's the goal anyway after reading ALL everyone wrote here.

I'll attach the target I have found and will be using....unless someone has something better or more accurate.

I will use that target for:
1. Eotech HWS EXPS2-GRN & 2. Troy Ind. flip up Iron Back Up, Round/M4, sights for my 100yd zero
3. Streamlight TLR-2 HL GRN Laser will be up front under barrel and set at a "constant offset"...point straight out parallel to bore.

Thanks again you guys. I guess I am one of those very meticulous guys who leans toward trying to master things. Heck, it takes me over an hour to field strip and clean my handgun after every range outing...which is NOT NORMAL....lol. I was a competitive gymnast in my younger days....guess I get that from that!!!

 

[scout0610]

Glad you have a solid game plan figured...I think you could say most of us here are into striving for a good bit better than average, so being meticulous puts you in familiar company. Good luck.

 

[KM1]

Thanks. I am impressed with the willingness to help and degree of knowledge here at snipers hide. Everyone was great!!!

 

[MontanaMan]

Just don't get caught up with "analysis paralysis" BS.................pick a sight scheme, set the gun to whatever your zero range is & then actually shoot your loads at various distances & make your own trajectory & cheat sheet for that gun, that sight/optic & that ammo.

Not really very complicated.........................

MM

 

[KM1]

Just don't get caught up with "analysis paralysis" BS.................pick a sight scheme, set the gun to whatever your zero range is & then actually shoot your loads at various distances & make your own trajectory & cheat sheet for that gun, that sight/optic & that ammo.

Not really very complicated.........................

MM

Yep....that will be the plan. Based on everything I've read here, and elsewhere, I think the best plan for me is to use that 100 yard zero and follow the plan you just outlined. Stick with that, then simply train/practice using that zero and LEARN the gun and the ammo I use out of that gun. RATHER than get into every little detail of every load possible and analyzing everything.

Nope, not very complicated once one decides on the best zero....that was my problem....had NO idea which way to go before this....and SOOOO much out there touting one or another scheme.

Thanks!!!

 

[slothlacrosse]

I hate when I feel like I actually contributed to a thread only to have @Molon drop a knowledge bomb that has me reevaluating all of my life choices.

 

[M8541Reaper]

36/300
Boom. Done.
But honestly it doesn’t matter which one you do if you know your holds...which you should.

 

[KM1]

36/300
Boom. Done.
But honestly it doesn’t matter which one you do if you know your holds...which you should.

This is like starting all over again when I started training with a handgun. I was new to that a while ago....learning curve was fun....and interesting. This will be a whole new thing. Plus, as I mentioned on another post seeking advice, I am right handed and left eye dominant. This adds a whole other dimension, issue, for me shooting a rifle. Not as easy to adapt as it was with a pistol. This is why I went with an Eotech as my optic...it allows both eyes open and, hopefully, I can train my weaker eye to sight through the optic/reticle and STILL use my dominant eye for handgun work.

GEEEZ....is anything ever easy....LOL!!!

 

[AMGtuned]

36/300
Boom. Done.
But honestly it doesn’t matter which one you do if you know your holds...which you should.

I found this to work also. Used to do the 50yd thing for irons/rds. Theres a great thread here somewhere, with a video link, that explains it all well.

 

[CBDR]

Enjoy the process. Then stick with it. Slow is smooth & smooth is fast. 100m zero = aim one inch high @ 25m. Hornady Black 75gr BTHP 223 Rem is a great round.

 

[Molon]

As requested by the OP . . .

62 grain TBBC

LE223T3

Federal XM556FBIT3

Federal XM556SBCT3

....

 

[TheGerman]

We always used a 50y with M193/M855. I think there's an argument lately making the shorter 36y zero 'better'.

The thing with the 50y zero was regardless of if you were using a EoTech or Aimpoint, anything less than a perceived 50 yard target distance you put the Aimpoint dot on the top of their head or the EoTech bottom ring on their face.

Otherwise for combat shooting where you didn't have time to figure out the distance (they were either <50yards = face hold, 50+ yards to 200 = center torso hold, more than 200+ = back to face hold).

Obviously if you had time for a more precise shot you would, but this is for everything from CQB to suppression where you don't have to try and remeber anything outside of your perceived distance to them and 1 of 2 holds. This works because without a magnified optic, you're not going to be able to split hairs at 100+ yards anyways given time restrictions and movement. Anything less, and you need to get accurate rounds on target and not worry about hitting them in a specific button on their shirt or whatever.

Don't be that butterbar shooting into the berm infront of him because you forgot your holds.

 

[KM1]

As requested by the OP . . .

62 grain TBBC

LE223T3

Federal XM556FBIT3

Federal XM556SBCT3

....

Thanks Molon....I did see this info from you on the net. They are pretty close in many ways with the federal round winning out by a little.

I didn't s

As requested by the OP . . .

62 grain TBBC

LE223T3

Federal XM556FBIT3

Federal XM556SBCT3

....

Thanks Molon....I did see this info from you on the net. They are pretty close in many ways with the federal round winning out by a little.

I didn't see accuracy though for the Gold Dot....just the Federal LE223T3.

Does the Gold Dot have the same accuracy out of the 16" barrel that the federal does.

Based on your data here it looks like the Fusion might be the best out of these rounds...if I'm reading this correctly.

 

[KM1]

We always used a 50y with M193/M855. I think there's an argument lately making the shorter 36y zero 'better'.

The thing with the 50y zero was regardless of if you were using a EoTech or Aimpoint, anything less than a perceived 50 yard target distance you put the Aimpoint dot or the EoTech bottom ring on their face.

Otherwise for combat shooting where you didn't have time to figure out the distance (they were either <50yards = face hold, 50+ yards to 200 = center torso hold, more than 200+ = back to face hold).

Obviously if you had time for a more precise shot you would, but this is for everything from CQB to suppression where you don't have to try and remeber anything outside of your perceived distance to them and 1 of 2 holds. This works because without a magnified optic, you're not going to be able to split hairs at 100+ yards anyways given time restrictions and movement. Anything less, and you need to get accurate rounds on target and not worry about hitting them in a specific button on their shirt or whatever.

Don't be that butterbar shooting into the berm infront of him because you forgot your holds.

For urban self defense I didn't think it likely to have to shoot over 100yds....let alone over 200yds.

I wanted to keep that deviation from 0 to 100yds only about 1 inch or so and I figured a slight high hold with the 1moa dot from 0 to 50yds and POA/POI 50 to 100yds would, as a hole, be easiest. For precision close shots to 10yds...the lower slash is the hold.

Anything 150 or longer one would need holdovers and, as you said, a magnifier. The likelyhood of that in self defense urban environments, I would think, would be very small .

It is that smallest deviation of bullet travel that seemed to be best with that 100yd zero for 0 to 100+yds. At least that is how I figured it... but admittedly I could be off about this.

 

[TheGerman]

For urban self defense I didn't think it likely to have to shoot over 100yds....let alone over 200yds.

I wanted to keep that deviation from 0 to 100yds only about 1 inch or so and I figured a slight high hold with the 1moa dot from 0 to 50yds and POA/POI 50 to 100yds would, as a hole, be easiest. For precision close shots to 10yds...the lower slash is the hold.

Anything 150 or longer one would need holdovers and, as you said, a magnifier. The likelyhood of that in self defense urban environments, I would think, would be very small .

It is that smallest deviation of bullet travel that seemed to be best with that 100yd zero for 0 to 100+yds. At least that is how I figured it... but admittedly I could be off about this.

For your purpose the 50y is fine, as it is for most. This isn't precision shooting especially with non magnified EoTechs or Aimpoints. At closer ranges, know where the hold is to a point where its reactive; if a target to me is 15y away, when I bring the gun up I'm instinctively aiming for the head/face area whereas most people will aim dead center and wonder why they are low.

There's also the sweet spot of awesome, where with the 50y zero and a head/face hold, you'll rock them square in the face.

You dont need a magnifier for a carbine for longer distances as the zero 'system' helps with that; the mentality is you're looking to suppress them well (i.e. not just randomly shoot ammo, but get it in their direction/very close) while moving or when its your turn to be the cover man during F&M/displacement. It's a balance of speed and accuracy you're looking for and the 50y zero helps with that so you're not stuck adjusting shit or trying to figure out ranges or whatever. You're shooting at a target, unknown but guesstimated range, and the 'system' of your zero and the rounds' exterior ballistics really help each other with that.

 

[KM1]

For your purpose the 50y is fine, as it is for most. This isn't precision shooting especially with non magnified EoTechs or Aimpoints. At closer ranges, know where the hold is to a point where its reactive; if a target to me is 15y away, when I bring the gun up I'm instinctively aiming for the head/face area whereas most people will aim dead center and wonder why they are low.

There's also the sweet spot of awesome, where with the 50y zero and a head/face hold, you'll rock them square in the face.

You dont need a magnifier for a carbine for longer distances as the zero 'system' helps with that; the mentality is you're looking to suppress them well (i.e. not just randomly shoot ammo, but get it in their direction/very close) while moving or when its your turn to be the cover man during F&M/displacement. It's a balance of speed and accuracy you're looking for and the 50y zero helps with that so you're not stuck adjusting shit or trying to figure out ranges or whatever. You're shooting at a target, unknown but guesstimated range, and the 'system' of your zero and the rounds' exterior ballistics really help each other with that.

Now you got me rethinking this.

 

[TheGerman]

Now you got me rethinking this.

As far as what?

We were basically in agreement.

 

[KM1]

I was working off a 100yd zero...not 50. My thought process was that this would minimize the deviation of bullet travel between 0 to 100yds by simply aiming 1" high 0 to 50 and 1moa dot right on 50 to 100.....done. This, if I had figured this right, would put any shot POI around 1" or less to right on at 100.

With a 50yd zero I would be under below 25yds and over 2" or so at 100yds. Both an under and an over. With the 100yd zero you are only under so a slight rise with the 1MOA dot to 50 would minimize that under keeping that ribbon of deviation very small. Point and shoot. That was my original thnking after reading all posts and looking at the ballistics of the rounds I am considering through a 16" barrel.

 

[TheGerman]

I was working off a 100yd zero...not 50. My thought process was that this would minimize the deviation of bullet travel between 0 to 100yds by simply aiming 1" high 0 to 50 and 1moa dot right on 50 to 100.....done. This, if I had figured this right, would put any shot POI around 1" or less to right on at 100.

With a 50yd zero I would be under below 25yds and over 2" or so at 100yds. Both an under and an over. With the 100yd zero you are only under so a slight rise with the 1MOA dot to 50 would minimize that under keeping that ribbon of deviation very small. Point and shoot. That was my original thnking after reading all posts and looking at the ballistics of the rounds I am considering through a 16" barrel.

No need to overthink, and you basically said it according to Molon's charts; with a 50yd zero, you'll never be more than 1.4 inches (2 inches) either way of the zero out to 200.

And seeing as how we're not trying to hit the bullseye, why make anything more difficult than it has to be?

Up close defensive distances - aim for the lower face.

Past 50 out to a perceived 200 - aim center with the dot/reticle.

Past that, aim for the face.