View Full Version : 36yd lpvo zero pros and cons
I’ve read the stickies and done some research on the web but I’m not finding anything that refers to this zeros pros and cons in an urban environment. What’s the forums opinions and why? Is it better or pretty much the same as a 50/200. Is the poi significant enough to go from one to the other?
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Short zeros always disappointed me when I moved out. Some people can make this stuff work, but I don't even zero NON-magnified inside of 100 yards.
People zero magnified optics at 36 or 50 yards?
I personally would never consider zeroing a magnified optic at any distance under 100 yards. Many LPVOs incorporate BDC reticles that incorporate a 200 yard zero at the reticle intersection and 300, 400, 500, etc hash marks below it.
I’ve read the stickies and done some research on the web but I’m not finding anything that refers to this zeros pros and cons in an urban environment. What’s the forums opinions and why? Is it better or pretty much the same as a 50/200. Is the poi significant enough to go from one to the other?
Sent from my iPhone using Tapatalk
Its a perfectly reasonable zeroing strategy, provided you have enough barrel. As with all near/far zero schemes, checking the far POI is advisable.
Let run some math, with calculations based on a 77 gr Nosler CC @ 2700 FPS at 200 ft ASL:
36 yd zero - Zero's again at about 255 yds Hight Above or Drop below of less than 2" 25-75 yds. Drop @ 500 yds 2.5 MIL or 44.5"
50 yd Zero - Zero's again at about 200 yds. Hight Above or Drop Below of less than 2" 25-225 yds. Drop @ 500 yds 3.0 MIL or 53.2"
100 yd - Doesn't zero again anywhere. Hight Above or Drop Below of less than 2" 25-175 yds. Drop @ 500 yds 3.3 Mil or 60.2"
I use a 50 yd zero for my AR's. It's most useful in that you have a 200 yd window when your bullet is never more than 2" above or below your point of aim. But I do verify my zero out to all ranges up to 500 yds, which is the furthest distance I have readily available.
So what you are saying is for the average commando, unless the bad guy is jumping around doing jumping jacks in an orange shirt you will hit him regardless of zero type?
Let run some math, with calculations based on a 77 gr Nosler CC @ 2700 FPS at 200 ft ASL:
36 yd zero - Zero's again at about 255 yds Hight Above or Drop below of less than 2" 25-75 yds. Drop @ 500 yds 2.5 MIL or 44.5"
50 yd Zero - Zero's again at about 200 yds. Hight Above or Drop Below of less than 2" 25-225 yds. Drop @ 500 yds 3.0 MIL or 53.2"
100 yd - Doesn't zero again anywhere. Hight Above or Drop Below of less than 2" 25-175 yds. Drop @ 500 yds 3.3 Mil or 60.2"
I use a 50 yd zero for my AR's. It's most useful in that you have a 200 yd window when your bullet is never more than 2" above or below your point of aim. But I do verify my zero out to all ranges up to 500 yds, which is the furthest distance I have readily available.
Short zeros always disappointed me when I moved out. Some people can make this stuff work, but I don't even zero NON-magnified inside of 100 yards.
https://external-content.duckduckgo.com/iu/?u=https%3A%2F%2Fmedia1.tenor.com%2Fimages%2Fc61211fc20030e9c8fcd81f467256044%2Ftenor.gif%3Fitemid%3D16589344&f=1&nofb=1&ipt=d7837f6cc8b26f241ee6463af2ee43c44e8ed92aca9bd481d36c1abde72cd93d&ipo=images
Short zeros always disappointed me when I moved out. Some people can make this stuff work, but I don't even zero NON-magnified inside of 100 yards.
This.
I zero at the far end and confirm at the first one.
ViniVidivici
03-29-23, 08:25
I zero all irons and RDS at 50yd, all magnified optics at 100, personal preferrence.
I guess it really doesn't matter, as long as you learn YOUR dope with what you've got.
Not that it matters to anyone, but I use 36/300 for my Aimpoints. I have the ability to safely shoot rocks and dirt clods at unknown ranges, so without using calculus, I'm able to use different shooting positions and just shoot shit. Works good for this country boy.
Edit: somebody feel free to delete this as it has nothing to do with lvpos, apologies.
Sidneyious
03-29-23, 16:41
https://youtu.be/HFE-wj7sOs0
The 36 yard zero was originally nothing more than a field expedient distance (near zero) for obtaining a 300 yard far zero when using the M16A2 with its 20” barrel firing M855.
https://www.ar15.com/media/mediaFiles/28568/36_300_yard_zero_01-2251420.jpg
Pop quiz.
What is the most commonly missed target on the US Army 300 meter pop-up range, when using a 300 meter zero?
a.) 50 meter target
b.) 150 meter target
c.) 300 meter target
d.) None of the above
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.)
https://www.ar15.com/media/mediaFiles/28568/100_yard_zero_data_01-1301858.jpg
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.
https://www.ar15.com/media/mediaFiles/28568/positive_elevation-1301877.gif
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.
https://www.ar15.com/media/mediaFiles/28568/negative_elevation-1301880.gif
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.
https://www.ar15.com/media/mediaFiles/28568/absolute_value_of_poi_from_poa_02-1301881.jpg
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.
Now, let’s add the 36 yard zero into the mix.
https://www.ar15.com/media/mediaFiles/28568/36_yard_zero_003-1726840.jpg
From the muzzle to approximately 42 yards, the 36 yard zero has a slight advantage over the 50 yard zero. From 50 yards out to approximately 235 yards, the 50 yard zero has a distinct advantage over the 36 yards zero. It isn’t until shooting past the distance of approximately 235 yards that the 36 yard zero regains any advantage over the 50 yard zero. Choose your zeroing scheme based on the pertinent facts.
Some reference material. Except where noted, all barrel lengths are 20 inches
https://www.ar15.com/media/mediaFiles/28568/trajectory_with_sight_illustration_from_-1301869.jpg
Courtesy of zrxc77
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M855 25 yard zero
https://www.ar15.com/media/mediaFiles/28568/M855_25_yard_zero_from_20_inch_barrel_-1301862.jpg
M855 25 meter zero
https://www.ar15.com/media/mediaFiles/28568/M855_25_meter_zero_from_20_inch_barrel_0-1301861.jpg
M855 36 yard vs 100 yard zero
https://www.ar15.com/media/mediaFiles/28568/M855_36_vs_100_yard_zeros_20_inch_barrel-1301863.jpg
M855
https://www.ar15.com/media/mediaFiles/28568/25_meter_zero_versus_300_meter_zero_02-1301913.jpg
M855 and M193 25 meter zero
https://www.ar15.com/media/mediaFiles/28568/m855_and_m193_25_meter_zero_from_20_inch-1301865.jpg
M855 and M193 50 yard zero from 16” barrel
https://www.ar15.com/media/mediaFiles/28568/M855_vs_M193_16_inch_barrel-1301924.jpg
M193 25 meter, 50 yard and 100 yard zeros from 16" barrel
https://www.ar15.com/media/mediaFiles/28568/m193_from_16_inch_barrel_25_50_and_100_z-1301860.jpg
100 yard zero
https://www.ar15.com/media/mediaFiles/28568/m855_and_m193_100_yard_zero_from_20_inch-1301867.jpg
25 meter vs 50 yard zero, M855 from 16” barrel
https://www.ar15.com/media/mediaFiles/28568/50_yard_versus_25_meter_zero_with_M855_f-1301857.jpg
25 meter vs 50 meter zero , M193 from 16" barrel
https://www.ar15.com/media/mediaFiles/28568/50_yard_versus_25_meter_zero_with_M855_f-1301857.jpg
M855 300 meter zero
https://www.ar15.com/media/mediaFiles/28568/300_meter_zero_02-1301859.jpg
M855 200 meter vs 300 meter zeros
https://www.ar15.com/media/mediaFiles/28568/M855_200_meter_vs_300_meter_zero_with_20-1301864.jpg
M855 36 yard vs 50 yard zeros
https://www.ar15.com/media/mediaFiles/28568/36_yard_vs_50_yard_zero_from_20_inch_bar-1301856.jpg
my guess is 150, the boys who insisted on 25 zero's always seemed to be winged shots high as f at the 100 yard plates
Not that it matters to anyone, but I use 36/300 for my Aimpoints. I have the ability to safely shoot rocks and dirt clods at unknown ranges, so without using calculus, I'm able to use different shooting positions and just shoot shit. Works good for this country boy.
Edit: somebody feel free to delete this as it has nothing to do with lvpos, apologies.
No need to delete it, I think the point stands on its own merit. As you point out, with what you are shooting, that zero method works for your needs. If MarkM was to use that same sighting in for shooting at 1000 yards, it would be wasted. However, if you were to use MarkMs method for your own needs, it would also be worthless. Without knowing what our objectives are, sometimes we are chasing an end goal we can never reach.
I zero all my gear at 100 yards and yet I can take my AR's to our pistol range and not miss whether it be 10 yards or 75 yards. The close targets are slants and a 6 pack of those MGM 8 inch MLS targets.
I think 2/3 inches in most combat situations is irrelevant. Long range precision DOPE is another story. I was shocked when I 100 yard zeroed my 10.5 LMT with 3 foot tall Unity mount and made consistent hits up close. I felt like I had everything against me but the gun went bang and the target popped.
Hence, we probably go overkill on worrying about 25/36/100 yard zeroes. Like said already, sight in and confirm via actually shooting. YMMV
PB
What is the reticle for your LPVO?
I had my Steiner P4Xi zeroed at 200 yards for the simple fact that was what the reticle called for. Was the BDC exact out at range? No. But they were on enough out to 500 yards that they would still score first round hits on IPSC steel.
For my red dots I like the 50 yard zero. Whether it's a little high or a little low at 200 yards doesnt really matter. Not that I can even realistically hold the difference at 200 yards with a red dot. I use it as a combat zero that gets me good COM hits from 0-300 yards. If it starts getting out towards the outer edge of the envelope, I just favor high on the target.
As to the original question... the 36 yards zero works. The 100 yard zero works. The 50 works.
Look at the graphs that Molon provided and choose the one you like most. They all have their pros and cons.
This video explains some benefits of different zeros.
https://www.youtube.com/watch?v=uAtU4lx2j_8
I zero all my guns 1" high at 100yds. I do this to extend no-hold range while eliminating hold-unders.
Then I get dope as far as the rifle will reliably hit.
What zero you choose doesnt really matter, learning holds does. Its going to be different based on load, optic hight, barrel length, etc
I zero all our carbines with open sights or red dots at 50 yards which also zero's around 220 yards. All scopes get zeroed at 100 yards except for my 280 Rem. I zero that at 200 yards which is almost two inches high at 100 yards.
NYH1.
vicious_cb
03-30-23, 18:04
What is the reticle for your LPVO?
I had my Steiner P4Xi zeroed at 200 yards for the simple fact that was what the reticle called for. Was the BDC exact out at range? No. But they were on enough out to 500 yards that they would still score first round hits on IPSC steel.
For my red dots I like the 50 yard zero. Whether it's a little high or a little low at 200 yards doesnt really matter. Not that I can even realistically hold the difference at 200 yards with a red dot. I use it as a combat zero that gets me good COM hits from 0-300 yards. If it starts getting out towards the outer edge of the envelope, I just favor high on the target.
Pretty much this, its all about the reticle. Just download Strelok and pick the zero that will make your preferred ammo match up the best with your BDC or whatever reticle you are running. As long as they end roughly matching the hash marks and you know what distances each mark corresponds to it doesnt matter which distance your zero is at.
The 36 yard zero was originally nothing more than a field expedient distance (near zero) for obtaining a 300 yard far zero when using the M16A2 with its 20” barrel firing M855.
Pop quiz.
What is the most commonly missed target on the US Army 300 meter pop-up range, when using a 300 meter zero?
a.) 50 meter target
b.) 150 meter target
c.) 300 meter target
d.) None of the above
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.
Now, let’s add the 36 yard zero into the mix.
From the muzzle to approximately 42 yards, the 36 yard zero has a slight advantage over the 50 yard zero. From 50 yards out to approximately 235 yards, the 50 yard zero has a distinct advantage over the 36 yards zero. It isn’t until shooting past the distance of approximately 235 yards that the 36 yard zero regains any advantage over the 50 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
Thanks for posting all of that. Kind of surprised it even needed to be explained.
I set up different rifles, different.
Scoped bolts I tend to 100 yard zero and rely on my range book.
AR carbines are almost always double zeroed because they can be an indoor / outdoor rifle.
The important thing is to actually shoot your rifles no matter what zero you are using. If you are using a double zero you want to confirm both distances, everything between and everything short of your close zero.
Thanks for posting all of that. Kind of surprised it even needed to be explained.
I set up different rifles, different.
Scoped bolts I tend to 100 yard zero and rely on my range book.
AR carbines are almost always double zeroed because they can be an indoor / outdoor rifle.
The important thing is to actually shoot your rifles no matter what zero you are using. If you are using a double zero you want to confirm both distances, everything between and everything short of your close zero.
My “plinking” rifles aka home defense SBRs (under 300 yards) are 50/200 and, like the above gent, my distance-oriented rifles (Tikka 6.5CM & 22” Hbar 5.56 & CLE Hbar) are zeroed at 100 with dope cards.
I might use a 36 if I was required to engage targets at distance, but I’m more likely to need to “fix bayonets” as a civilian, or choose the available tool at the moment since I don’t live in an area where I would be required to shoot 325 yard out bad guy, hence my choices. And, if I did know, Tikka or CLE would be my choice.
YMMV
Me: 1x RDS, 50yd, verifying the ~200 crossover. 1-6x or 8x LPVO, 100yd, dope trued as far as range allows.
The important thing is to actually shoot your rifles no matter what zero you are using. If you are using a double zero you want to confirm both distances, everything between and everything short of your close zero.
This. If you don't actually shoot and know it, it's all just academic.
Me: 1x RDS, 50yd, verifying the ~200 crossover. 1-6x or 8x LPVO, 100yd, dope trued as far as range allows.
This. If you don't actually shoot and know it, it's all just academic.
This is how I set mine up as well. I have one more option, my purely hunting rifles are zeroed to MPBR as I find that works best for me in that particular situation.
I verify my hunting rig at the range every year prior to taking it out as it probably wasn't shot off season.
vicious_cb
04-01-23, 16:33
Ok, people are just throwing out their favorite zero like 50/200 without context. I repeat, if you are not using a referencesless reticle like a red dot, you are NOT trying to minimize your max ord. with a cookie cutter 50/200 zero, you are trying to match the particular cartridge to whatever reticle you are using so your reticle marks actually mean something. Which means you are using a ballistic calculator then confirming at the range if your POI is matching the reticle at the desired distances. If your POIs at common distances are just floating in space between your reference marks then there is no point in even having spent money on said reticle when you should have got an red dot magnifier instead.
As ST said, many LPVO reticles are built around a 100 yd zero with the center of the reticle with a particular cartridge and velocity, you may need to zero closer or further depending on how far your gun/ammo combo deviates from the reference cartridge.
The OP didn't specify what LPVO he's using, nor what type of reticle it uses, so my guess is that he's not looking for information specific to his setup.
Most LPVO reticles incorporate elevation holdover hash marks in MOA, MILs, or BDC, so the MPBR concept generally isn't utilized. If the OP's recicle is just a duplex crosshair, then it's best to treat it like a RDS and determine the appropriate zero based on his expected target distances and size.
The Trijicon Credo HX reticle is for a 50/200 yard zero.
Trijicon Credo HX 1-6x24: A Quick Look
https://www.ar15.com/media/mediaFiles/28568/triarc_rilfe_trijicon_credo_hx_002_resiz-2598072.jpg
One of Trijicon’s more recent entries into the very crowded low-power variable optic market is the Credo HX 1-6x24. Trijicon produces six different versions of the Credo HX 1-6x24. This article spotlights the version with the bullet-drop compensating “Hunter Holds” reticle for 223 Remington, with the LED red dot; SKU number CRHX624-C-2900020
Trijicon is marketing this optic as a “hunting riflescope,” hence the “Hunter Holds” reticle nomenclature. Despite this optic’s relatively late entry into the LPVO market, it’s gaining favor with the AR-15 defensive shooting crowd; and for good reasons. The Credo HX is not “the best” in any of the relevant metrics. However, for those who prefer a second focal plane LPVO on a defensive rifle and aren't interested in defined ranging capabilities, the Credo HX checks many of the preferred boxes, the least of which is a very reasonable price tag for an optic of this quality.
https://www.ar15.com/media/mediaFiles/28568/trijicon_credo_hx_003-2598073.jpg
The Trijicon Credo HX 1-6x24 is not the lightest LPVO in its category, but it’s not the heaviest either. Without a mount or lens covers, the Credo HX has a weight of 1 pound, 2.7 ounces.
https://www.ar15.com/media/mediaFiles/28568/trijicon_credo_hx_weight_01-2598076.jpg
The optic is supplied with bikini-style lens covers and a neoprene scope cover. It also comes with a small magnification-ring throw-lever that can be positioned in two different locations on the ring.
https://www.ar15.com/media/mediaFiles/28568/credo_throw_lever_002-2598085.jpg
The diopter of the ocular lens is adjustable. The ¼ MOA windage and elevation turrets are capped and the turrets can be “zeroed out” by simply pulling up on the adjustment cap, spinning it to the desired location and pushing it back down.
https://www.ar15.com/media/mediaFiles/28568/credo_diopter_001-2598111.jpg
https://www.ar15.com/media/mediaFiles/28568/credo_turret_caps_001b-2598293.jpg
https://www.ar15.com/media/mediaFiles/28568/credo_elevation_cap_01-2598520.jpg
https://www.ar15.com/media/mediaFiles/28568/credo_elevation_turret_001-2598118.jpg
https://www.ar15.com/media/mediaFiles/28568/credo_elevation_turret_002-2598112.jpg
The bullet-drop compensating reticle on the Credo HX is based on the German #4 reticle. The Credo HX reticle has four stadia lines on the horizontal cross-hair for rudimentary windage and moving-lead hold-offs. The vertical cross-hair has five stadia lines to compensate for bullet-drops from 300 to 700 yards.
https://www.ar15.com/media/mediaFiles/28568/trijicon_credo_hx_reticle_01b-2598075.jpg
The come-ups of the BDC reticle are a damn near perfect match for my 55 grain loads.
https://www.ar15.com/media/mediaFiles/28568/trijicon_BDC_Hunter_Holds__223__Credo_HX-2599179.jpg
A rough check at 50 yards of the BDC come-ups shows that they are just as advertised. Obviously, since this is a second focal plane reticle, those particular bullet drop compensations only apply with the magnification set a 6X.
https://www.ar15.com/media/mediaFiles/28568/trijicon_credo_hx_50_yards_001c-2599176.jpg
https://i.ibb.co/gSsDtMx/triarc-rifle-003-resized-framed-c.jpg
For those of you who expressed an interest in my target shown above, you can down-load a .pdf file of it here. (https://drive.google.com/file/d/17if13v9tlluplZrWMPN-o8331sT1eKvA/view?usp=sharing)
Now, for the more ponderous aspect of this short review; the brightness of the red dot. The LED red dot on the Credo HX is powered by a CR2032 battery which is housed in the brightness adjustment turret. The turret has ten brightness settings with an "off" setting in between each of the brightness levels. The battery powered LED red dot of the Credo HX is definitely daylight bright. If I had to make a subjective comparison, to my MK 1 eyes, the brightness of the red dot on the Credo HX is nearly as bright as the second highest brightness setting on the Aimpoint Comp M5. Even in a manipulated scenario with the brightest outdoor ambient lighting I could find (short of looking into the sun), the dot was still slightly visible.
To demonstrate the above comparison, I took a couple of pictures, outdoors, on a cloudless day. The Credo HX was aimed at a reflective, white garage door with the sun shining at the door from approximately 04:30 behind me.
The first picture shown below is a view of an Aimpoint Comp M5 positioned in a shaded area and aimed at the bright white garage door with the brightness setting on the second highest level. (Keep in mind that the 2 MOA dot of the Aimpoint Comp M5 appears at least two times as large as the red dot on the Credo HX in this example.)
https://www.ar15.com/media/mediaFiles/28568/aimpoint_comp_m5_2nd_highest_setting_001-2598227.jpg
The next picture shows the same view, now through the Credo HX set at 1X magnification positioned in the shaded area with the brightness setting on “10”. The illumination of many of the low-power variable optics on the market would be completly washed out in this scanario.
https://i.ibb.co/8B95kJL/trijicon-credo-hx-red-dot-trijicon-001b.jpg
The last pic shows the red dot of the Credo HX aimed at an actual target.
https://i.ibb.co/fxhS9yD/trijicon-credo-hx-red-dot-002b.jpg
…..
Sidneyious
04-01-23, 21:40
I don’t live in an area where I would be required to shoot 325 yard out bad guy, hence my choices. And, if I did know, Tikka or CLE would be my choice.
YMMV
I thought the same thing till I was using a range finder sitting on my porch looking down the neighborhood.
So I took a 16" upper and made it a 500y upper.
I thought the same thing till I was using a range finder sitting on my porch looking down the neighborhood.
So I took a 16" upper and made it a 500y upper.
That’s why i have a Tikka in 6.5CM & Compass Lake Engineering SAM-R sighted in at 100 yards & DOPE for my handloads in 6.5CM & Black Hills 77gr TMK & DOPE. I’m in suburbia & honestly wish Claymores were an option in the times of civil unrest due to nothing being over 200 yards LOS. Given certain wilding groups tendency to toss Molotovs, I think the right tool isn’t readily available.
Pop quiz.
What is the most commonly missed target on the US Army 300 meter pop-up range, when using a 300 meter zero?
a.) 50 meter target
b.) 150 meter target
c.) 300 meter target
d.) None of the above
The 300 meter target . . .
I could only guess, but after using that 25/300 zero I would say 150m.
The 300 meter target . . .
Hahaha, just need to bear down harder.
Think about it . . .
The required dispersion of an Army shooter/M4/M855A1 combination is 5.4 inches at 91.4 meters (4 cm at 25 meters). So at 300 meters that spread is 18-3/4 inches. The "E" target is 19.5 inches wide, so you have 3/8 inch to spare, side-to-side, if you are perfectly lined up on the target. Now throw in the fact that the lateral zero is based on a three shot group, possibly 4 cm extreme spread, a shooter that this is the first time in six months (at best) shooting, and feels a time crunch, because he/she didn't actually see it pop up so isn't quite sure when that 8 seconds is over.
These are not NRA Experts, these are truck drivers, supply clerks, hospital orderlies, and mechanics, that do this one day, twice a year.
According to the Army's data, a properly zeroed M4 will have a maximum ordinate of 8 inches at 175 meters. If you look at a Army zero target, and hold the sights on the center of that 4 cm circle, he impact point at 150 meters will be about the top of that 4 cm circle, or about in the center of the silhouette's heart.
EDIT: In fact, the percentage hits on the Army qualification course decreases almost linearly with respect to distance.
https://i.imgur.com/lePZltg.jpg
Think about it . . .
The required dispersion of an Army shooter/M4/M855A1 combination is 5.4 inches at 91.4 meters (4 cm at 25 meters). So at 300 meters that spread is 18-3/4 inches. The "E" target is 19.5 inches wide, so you have 3/8 inch to spare, side-to-side, if you are perfectly lined up on the target. Now throw in the fact that the lateral zero is based on a three shot group, possibly 4 cm extreme spread, a shooter that this is the first time in six months (at best) shooting, and feels a time crunch, because he/she didn't actually see it pop up so isn't quite sure when that 8 seconds is over.
These are not NRA Experts, these are truck drivers, supply clerks, hospital orderlies, and mechanics, that do this one day, twice a year.
According to the Army's data, a properly zeroed M4 will have a maximum ordinate of 8 inches at 175 meters. If you look at a Army zero target, and hold the sights on the center of that 4 cm circle, he impact point at 150 meters will be about the top of that 4 cm circle, or about in the center of the silhouette's heart.
EDIT: In fact, the percentage hits on the Army qualification course decreases almost linearly with respect to distance.
https://i.imgur.com/lePZltg.jpg
I was there with an M14, I hit it.
The 36 yard zero was originally nothing more than a field expedient distance (near zero) for obtaining a 300 yard far zero when using the M16A2 with its 20” barrel firing M855.
https://www.ar15.com/media/mediaFiles/28568/36_300_yard_zero_01-2251420.jpg
Pop quiz.
What is the most commonly missed target on the US Army 300 meter pop-up range, when using a 300 meter zero?
a.)50 meter target
b.)150 meter target
c.)300 meter target
d.)None of the above
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.)
https://www.ar15.com/media/mediaFiles/28568/100_yard_zero_data_01-1301858.jpg
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.
https://www.ar15.com/media/mediaFiles/28568/positive_elevation-1301877.gif
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.
https://www.ar15.com/media/mediaFiles/28568/negative_elevation-1301880.gif
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.
https://www.ar15.com/media/mediaFiles/28568/absolute_value_of_poi_from_poa_02-1301881.jpg
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.
Now, let’s add the 36 yard zero into the mix.
https://www.ar15.com/media/mediaFiles/28568/36_yard_zero_003-1726840.jpg
From the muzzle to approximately 42 yards, the 36 yard zero has a slight advantage over the 50 yard zero. From 50 yards out to approximately 235 yards, the 50 yard zero has a distinct advantage over the 36 yards zero. It isn’t until shooting past the distance of approximately 235 yards that the 36 yard zero regains any advantage over the 50 yard zero. Choose your zeroing scheme based on the pertinent facts.
Some reference material. Except where noted, all barrel lengths are 20 inches
https://www.ar15.com/media/mediaFiles/28568/trajectory_with_sight_illustration_from_-1301869.jpg
Courtesy of zrxc77
.
.
.
M855 25 yard zero
https://www.ar15.com/media/mediaFiles/28568/M855_25_yard_zero_from_20_inch_barrel_-1301862.jpg
M855 25 meter zero
https://www.ar15.com/media/mediaFiles/28568/M855_25_meter_zero_from_20_inch_barrel_0-1301861.jpg
M855 36 yard vs 100 yard zero
https://www.ar15.com/media/mediaFiles/28568/M855_36_vs_100_yard_zeros_20_inch_barrel-1301863.jpg
M855
https://www.ar15.com/media/mediaFiles/28568/25_meter_zero_versus_300_meter_zero_02-1301913.jpg
M855 and M193 25 meter zero
https://www.ar15.com/media/mediaFiles/28568/m855_and_m193_25_meter_zero_from_20_inch-1301865.jpg
M855 and M193 50 yard zero from 16” barrel
https://www.ar15.com/media/mediaFiles/28568/M855_vs_M193_16_inch_barrel-1301924.jpg
M193 25 meter, 50 yard and 100 yard zeros from 16" barrel
https://www.ar15.com/media/mediaFiles/28568/m193_from_16_inch_barrel_25_50_and_100_z-1301860.jpg
100 yard zero
https://www.ar15.com/media/mediaFiles/28568/m855_and_m193_100_yard_zero_from_20_inch-1301867.jpg
25 meter vs 50 yard zero, M855 from 16” barrel
https://www.ar15.com/media/mediaFiles/28568/50_yard_versus_25_meter_zero_with_M855_f-1301857.jpg
25 meter vs 50 meter zero , M193 from 16" barrel
https://www.ar15.com/media/mediaFiles/28568/50_yard_versus_25_meter_zero_with_M855_f-1301857.jpg
M855 300 meter zero
https://www.ar15.com/media/mediaFiles/28568/300_meter_zero_02-1301859.jpg
M855 200 meter vs 300 meter zeros
https://www.ar15.com/media/mediaFiles/28568/M855_200_meter_vs_300_meter_zero_with_20-1301864.jpg
M855 36 yard vs 50 yard zeros
https://www.ar15.com/media/mediaFiles/28568/36_yard_vs_50_yard_zero_from_20_inch_bar-1301856.jpg
Impressive post. I personally zero my AR at 50 yards with a red dot. I can’t shoot past 100 yards without a magnified optic anyway. I’m a couple of inches high at 100 yards but good enough for a defensive situation. With my Acog, I zero at 100 yards and the hash marks are pretty right on out to 300 yards (the maximum range I have available to shoot). With my AKs, I zero at 50 yards with a red dot and they are right on at 100 yards. Keep it simple. If I ever had to shoot someone in a close in situation (same room), I just think, aim for the forehead and you will hit him in the middle of the face. Never forget your mechanical offset (height above bore of your optic that really matters close in. That’s all I got [emoji2369]
Sent from my iPhone using Tapatalk Pro
Sidneyious
04-05-23, 20:45
That’s why i have a Tikka in 6.5CM & Compass Lake Engineering SAM-R sighted in at 100 yards & DOPE for my handloads in 6.5CM & Black Hills 77gr TMK & DOPE. I’m in suburbia & honestly wish Claymores were an option in the times of civil unrest due to nothing being over 200 yards LOS. Given certain wilding groups tendency to toss Molotovs, I think the right tool isn’t readily available.I still think a good semiauto is preferred for urban ish areas.
Bolt gun for when you got open spaces so you can make real ruse of a heavier and higher bc round to make any real use.
I don't know about y'all but the whole bug in concept is just asking for your own cremation.
My Town is only 35k people, I live on the edge of town and can be on my way to somewhere else in 10 minutes.
I don't have a lot of stuff in my current hovel as it's in a storage unit somewhere else.
People always talk about not being able to buy land in the middle of nowhere but you can get a storage unit there.
I still think a good semiauto is preferred for urban ish areas.
Bolt gun for when you got open spaces so you can make real ruse of a heavier and higher bc round to make any real use.
I don't know about y'all but the whole bug in concept is just asking for your own cremation.
My Town is only 35k people, I live on the edge of town and can be on my way to somewhere else in 10 minutes.
I don't have a lot of stuff in my current hovel as it's in a storage unit somewhere else.
People always talk about not being able to buy land in the middle of nowhere but you can get a storage unit there.
I agree, and I can’t imagine taking a shot over 200 yards, hence my 25/200 zero preference, which was my reply to the topic of the thread. The out of context quote refers to other, better guns for distance shooting, which isn’t likely in my suburban world.
Bug out vs hunker down/bug in is another topic. I don’t have anything in storage. When people & cars clog highways & chaos is the goal of a mob and/or burning & looting is happening—every choice has positives & negatives.
So, you make a choice, take chances; prepare for the worst & hope for the best.
Now back to our regularly scheduled programming:D
I don't know about y'all but the whole bug in concept is just asking for your own cremation.
Nah, home turf. Limitless ammo. NY-reloads. Terrain. Traps.
But of course I have land. And allies.
:p
Nah, home turf. Limitless ammo. NY-reloads. Terrain. Traps.
But of course I have land. And allies.
:p
Yeah, the situation dictates.
For MSW, 500yds is sbr-14.5" territory. An SAM-R is a 700-1kyd rifle
Yeah, the situation dictates.
For MSW, 500yds is sbr-14.5" territory. An SAM-R is a 700-1kyd rifle
My SBRs are 12” with a red dot, so not for me. My Tikka is a better choice for 700-1K yards, IMO.
Sidneyious
04-07-23, 22:59
I agree, and I can’t imagine taking a shot over 200 yards, hence my 25/200 zero preference, which was my reply to the topic of the thread. The out of context quote refers to other, better guns for distance shooting, which isn’t likely in my suburban world.
Bug out vs hunker down/bug in is another topic. I don’t have anything in storage. When people & cars clog highways & chaos is the goal of a mob and/or burning & looting is happening—every choice has positives & negatives.
So, you make a choice, take chances; prepare for the worst & hope for the best.
Now back to our regularly scheduled programming:DI can't imagine living in a place where you need to get on an interstate to get out of town.
5 minutes tops and I'm on a dirt and gravel county road.
I can't imagine living in a place where you need to get on an interstate to get out of town.
5 minutes tops and I'm on a dirt and gravel county road.
I wish….
I need people to do my job & better paying jobs are near populated cities.
I live at the end of a gravel road. You have to run the gauntlet of my Redneck neighbors and their yards full of dogs to even get close. We're watching.
Y’all don’t forget to set aside some food for me, too. I’m trying not to eat too many people when the world ends.*
Yes, long shots exist in cities. Thinking about those long shots is pretty deep in the weeds, and taking them is ill-advised in like 99% of scenarios I can cook up in my head. Taking long shots across denied, non-permissive or semi-permissive urban territory is like Russian Roulette….better not do it often. You’ll find out how often was too often by being dead, and I’m thinking of a number between zero and six.
*That was a joke.
The 36 yard zero was originally nothing more than a field expedient distance (near zero) for obtaining a 300 yard far zero when using the M16A2 with its 20” barrel firing M855.
https://www.ar15.com/media/mediaFiles/28568/36_300_yard_zero_01-2251420.jpg
Pop quiz.
What is the most commonly missed target on the US Army 300 meter pop-up range, when using a 300 meter zero?
a.)50 meter target
b.)150 meter target
c.)300 meter target
d.)None of the above
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.)
https://www.ar15.com/media/mediaFiles/28568/100_yard_zero_data_01-1301858.jpg
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.
https://www.ar15.com/media/mediaFiles/28568/positive_elevation-1301877.gif
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.
https://www.ar15.com/media/mediaFiles/28568/negative_elevation-1301880.gif
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.
https://www.ar15.com/media/mediaFiles/28568/absolute_value_of_poi_from_poa_02-1301881.jpg
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.
Now, let’s add the 36 yard zero into the mix.
https://www.ar15.com/media/mediaFiles/28568/36_yard_zero_003-1726840.jpg
From the muzzle to approximately 42 yards, the 36 yard zero has a slight advantage over the 50 yard zero. From 50 yards out to approximately 235 yards, the 50 yard zero has a distinct advantage over the 36 yards zero. It isn’t until shooting past the distance of approximately 235 yards that the 36 yard zero regains any advantage over the 50 yard zero. Choose your zeroing scheme based on the pertinent facts.
Some reference material. Except where noted, all barrel lengths are 20 inches
https://www.ar15.com/media/mediaFiles/28568/trajectory_with_sight_illustration_from_-1301869.jpg
Courtesy of zrxc77
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M855 25 yard zero
https://www.ar15.com/media/mediaFiles/28568/M855_25_yard_zero_from_20_inch_barrel_-1301862.jpg
M855 25 meter zero
https://www.ar15.com/media/mediaFiles/28568/M855_25_meter_zero_from_20_inch_barrel_0-1301861.jpg
M855 36 yard vs 100 yard zero
https://www.ar15.com/media/mediaFiles/28568/M855_36_vs_100_yard_zeros_20_inch_barrel-1301863.jpg
M855
https://www.ar15.com/media/mediaFiles/28568/25_meter_zero_versus_300_meter_zero_02-1301913.jpg
M855 and M193 25 meter zero
https://www.ar15.com/media/mediaFiles/28568/m855_and_m193_25_meter_zero_from_20_inch-1301865.jpg
M855 and M193 50 yard zero from 16” barrel
https://www.ar15.com/media/mediaFiles/28568/M855_vs_M193_16_inch_barrel-1301924.jpg
M193 25 meter, 50 yard and 100 yard zeros from 16" barrel
https://www.ar15.com/media/mediaFiles/28568/m193_from_16_inch_barrel_25_50_and_100_z-1301860.jpg
100 yard zero
https://www.ar15.com/media/mediaFiles/28568/m855_and_m193_100_yard_zero_from_20_inch-1301867.jpg
25 meter vs 50 yard zero, M855 from 16” barrel
https://www.ar15.com/media/mediaFiles/28568/50_yard_versus_25_meter_zero_with_M855_f-1301857.jpg
25 meter vs 50 meter zero , M193 from 16" barrel
https://www.ar15.com/media/mediaFiles/28568/50_yard_versus_25_meter_zero_with_M855_f-1301857.jpg
M855 300 meter zero
https://www.ar15.com/media/mediaFiles/28568/300_meter_zero_02-1301859.jpg
M855 200 meter vs 300 meter zeros
https://www.ar15.com/media/mediaFiles/28568/M855_200_meter_vs_300_meter_zero_with_20-1301864.jpg
M855 36 yard vs 50 yard zeros
https://www.ar15.com/media/mediaFiles/28568/36_yard_vs_50_yard_zero_from_20_inch_bar-1301856.jpg
Excellent post.
Defaultmp3
04-08-23, 19:21
Yeah, the situation dictates.
For MSW, 500yds is sbr-14.5" territory. An SAM-R is a 700-1kyd rifleWait, what? Using an SBR at 500 yards? And a SAM-R at 1k yards? Seems extraordinarily shakey to me. That might work on the square range, with a spotter, totally exposed static targets, without any thought given to terminal ballistics. Good luck doing that consistently in a duty situation. Sure you can push a 77 gr. pill out to 1k yards onto a human target and get good terminal effects. Doesn't mean that's the ideal choice to do it consistently.
Wait, what? Using an SBR at 500 yards? And a SAM-R at 1k yards? Seems extraordinarily shakey to me. That might work on the square range, with a spotter, totally exposed static targets, without any thought given to terminal ballistics. Good luck doing that consistently in a duty situation. Sure you can push a 77 gr. pill out to 1k yards onto a human target and get good terminal effects. Doesn't mean that's the ideal choice to do it consistently.
Its not ideal for those max distances, but it can be extended to those ranges. My comment was to him using a 6.5 tikka and/or samr for 325-500 yds. I was making a point that the rfles if set up properly can extend. I also said the situation dictates... meaning they are not ideal, but capable.
No spotter
16" 223:
Im hitting 12-15" plates at 700yds in 3-5 hits
1st round hits on 2/3 ipsc @ 650
11.5" 223:
1st round hits to 500 2/3 ipsc
Yeah, its oviously a "square range"
Id love to shoot movers at that range if you can tell me where that's happening.
And yes, im mush less worried about terminal performance at 500yds, though gold dots will mushroom out to 400.
Wait, what? Using an SBR at 500 yards? And a SAM-R at 1k yards? Seems extraordinarily shakey to me. That might work on the square range, with a spotter, totally exposed static targets, without any thought given to terminal ballistics. Good luck doing that consistently in a duty situation. Sure you can push a 77 gr. pill out to 1k yards onto a human target and get good terminal effects. Doesn't mean that's the ideal choice to do it consistently.
Its not ideal for those max distances, but it can be extended to those ranges. My comment was to him using a 6.5 tikka and/or samr for 325-500 yds. I was making a point that the rfles if set up properly can extend. I also said the situation dictates... meaning they are not ideal, but capable.
No spotter
16" 223:
Im hitting 12-15" plates at 700yds in 3-5 hits
1st round hits on 2/3 ipsc @ 650
11.5" 223:
1st round hits to 500 2/3 ipsc
Yeah, its oviously a "square range"
Id love to shoot movers at that range if you can tell me where that's happening.
And yes, im mush less worried about terminal performance at 500yds, though gold dots will mushroom out to 400.
Most shooters have no idea how hard a cold bore shot at unknown range really is.
At a LR match back in 2010, the first target was a cold bore shot. It was placed in the woods 615 yds from the firing line, it was a light gray painted 10" round steel plate.
The temperature was 35 degrees, and there was a slight 8 mph wind cross left to right. There were open fields before the woods were the target was placed. The range was unknown, as we were not told, and no laser range finders were allowed.
No warm upshots had been allowed, and you had to come to the match all ready to go.
In any event there were 27 shooters and 26 misses. Yup one hit. Among the shooters was a former Marine Scout sniper (who finished 2nd), and a active duty Green Beret (who won the match in a shoot off) and they both missed. I finished 3rd and missed it as well. The one shooter who hit finished near the bottom of the standings. Most shooters had .308's and there was a few 260 Rems as well. All heavy barreled, with 12x or higher scopes. I was using an FFP IOR Valdada 3-18x42mm on Rem 700 LTR rifle in .308.
70114
I was using an FFP IOR Valdada 3-18x42mm
How did that scope hold up for you? Do you still have it?
Disciple,
No I don't. It was my first FFP scope I sold after 2 years of hard use. It was a Gen 2 model by IOR as the first Gen scopes were more than problematic. When I sold it I bought a US Optics 3.2-17x44mm. I shot with that one for a 3 more years, and then bought a Vortex Razor II 3-18x50mm. It had great glass and turrets but was a heavy beast. My last LR rifle scope was Steiner T5Xi 3-15x50mm. Then old age and infirmity made me give up the LR game as I could no longer run and gun. Humping a 15 lb + rifle around a outdoor course of fire is a young man's game.
In between on various rifles I had a SWFA FFP 3-9x42mm, SWFA FFP 3-15x44mm, a pair of Bushnell FFP LRHS 3-12x44mm. I started like most LR shooters on Leupold Mark 4''s LR/T 3.5-10x40mm, but competitors soon passed them by. Matching reticles and turrets plus FFP was something Leupold was slow to adopt.
The biggest scope I now sport is a Trijcon Credo FFP 2-10x36mm for my DMR type 18" barreled AR15.
Most shooters have no idea how hard a cold bore shot at unknown range really is.
At a LR match back in 2010, the first target was a cold bore shot. It was placed in the woods 615 yds from the firing line, it was a light gray painted 10" round steel plate.
The temperature was 35 degrees, and there was a slight 8 mph wind cross left to right. There were open fields before the woods were the target was placed. The range was unknown, as we were not told, and no laser range finders were allowed.
No warm upshots had been allowed, and you had to come to the match all ready to go.
In any event there were 27 shooters and 26 misses. Yup one hit. Among the shooters was a former Marine Scout sniper (who finished 2nd), and a active duty Green Beret (who won the match in a shoot off) and they both missed. I finished 3rd and missed it as well. The one shooter who hit finished near the bottom of the standings. Most shooters had .308's and there was a few 260 Rems as well. All heavy barreled, with 12x or higher scopes. I was using an FFP IOR Valdada 3-18x42mm on Rem 700 LTR rifle in .308.
70114
Lets also acknowledge that is a 1.5moa target. That is an extremely difficult shot.
Did competitors know target size to facilitate reticle ranging?
Yes, they did give us the size. And we were each given 2 minutes to reticle range it.
And many ranged it as an even 600 yds. But the last 15 yds and the on and off again wind was enough to cause a miss.
But it was a very difficult cold bore shot. It was designed that way. One shot only.
Ranging is critical, especially at longer distances where the Danger Space becomes shorter as you go out.
Yes, they did give us the size. And we were each given 2 minutes to reticle range it.
And many ranged it as an even 600 yds. But the last 15 yds and the on and off again wind was enough to cause a miss.
But it was a very difficult cold bore shot. It was designed that way. One shot only.
Did you happen to ask anyone about their DOPE sources?
Did you happen to ask anyone about their DOPE sources?
Do you mean that wormy looking dude that is always hanging out in the 7-11 parking lot?
Did you happen to ask anyone about their DOPE sources?
We couldn't after each shooter fired his one shot, they were whisked off to the next shooting stage, away from where we who were waiting to shoot were gathered.
It was so designed that were could glen nothing from those who shot the stage before us.
After you shot it didn't much matter what their dope was.
Did you happen to ask anyone about their DOPE sources?
We couldn't after each shooter fired his one shot, they were whisked off to the next shooting stage, away from where we who were waiting to shoot were gathered.
It was so designed that way so that we could gleen nothing from those who shot the stage before us.
After you shot it and missed it didn't much matter what their dope was. Theirs was a bad as yours.
Allow me to clarify why I asked- missing at 615 on a 600yd range estimate might also be explained by punching stuff into an app. Every gun I’ve shot at that distance hits lower than I predicted. For example, I was shooting some large targets at that distance about a month ago, and I had to dial a little more than expected. When I checked the target later, even after getting my sight solution such that I was getting 100% hits, I noticed they were all clustered near the dirt. 15 more yards, and most might have been misses. This was with a Grendel, for reference. Of course, I can collect D.O.P.E. from actual previous engagements, like that acronym stands for, and move those impacts more appropriately on that cold shot.
Just something I was thinking about. I’m not claiming anything different from what you were saying.
Eta: Hornady ballistic technical support has an opinion of why published BCs (of no particular brand of bullet) sometimes don’t work, and claim to have a better mousetrap.
Hey, while I participated, may want to start another thread in the Precision Section as this thread is wandering a bit--kind of like sitting down to research a vacation and 2 hours later you are looking at midget porn
Hey, while I participated, may want to start another thread in the Precision Section as this thread is wandering a bit--kind of like sitting down to research a vacation and 2 hours later you are looking at midget porn
https://external-content.duckduckgo.com/iu/?u=https%3A%2F%2Fmedia1.tenor.com%2Fimages%2F1f2bd991489f88175025caefacf46403%2Ftenor.gif%3Fitemid%3D13185539&f=1&nofb=1&ipt=eb7917d045fa04424372fe6250e8b67cce509e826f6a54d74bf7dec446c8e413&ipo=images
All my AR-15's are of the 50/200 zero, regardless of optic.
FWIW, all our hunting rifles are also zeroed at 50 yards. They run from .243 win. to .325 WSM. At 100 yards yards none are over 1" high, and none drop less than 2 1/2" at 200 yards.
Eurodriver
05-31-23, 09:23
I run a 100y zero per the Great Jack Leuba.
ExplorinInTheWoods
06-04-23, 18:13
50yd zero or 100 if it has a BDC that calls for it. No mounts higher than 1.70 or lower 1/3. If you use unity mounts you probably think antifa members ought to have rights and probably registered your brace or actually destroyed it. I have not used a 36, but 25 is terrible. 100 is fine, I just can’t get a good enough zero with a dot at that distance.
I zero all irons and RDS at 50yd, all magnified optics at 100, personal preferrence.
I guess it really doesn't matter, as long as you learn YOUR dope with what you've got.
Exact same here. It helps that my home range is only 100y.
Colt Carson
06-05-23, 00:46
I zero all irons and RDS at 50yd, all magnified optics at 100, personal preferrence.
I guess it really doesn't matter, as long as you learn YOUR dope with what you've got.
Your close range sights are set up for longer range than your long range sights?
ViniVidivici
06-05-23, 08:00
Your close range sights are set up for longer range than your long range sights?
You're coming in broken and distorted, say again, over?
Defaultmp3
06-05-23, 08:17
All my AR-15's are of the 50/200 zero, regardless of optic.So... is it zeroed for 50 yards, or 200 yards?
If you use unity mounts you probably think antifa members ought to have rights and probably registered your brace or actually destroyed it.
https://media.tenor.com/u1V_-f-jXmcAAAAC/malreynolds-firefly.gif
50yd zero or 100 if it has a BDC that calls for it. No mounts higher than 1.70 or lower 1/3. If you use unity mounts you probably think antifa members ought to have rights and probably registered your brace or actually destroyed it. I have not used a 36, but 25 is terrible. 100 is fine, I just can’t get a good enough zero with a dot at that distance.
So you are telling everyone that you only have MEME tier range toys and not a real setup that is able to fight........... If you don;/t have a 1.93 scope mount then you have no IR laser...... go back to the kids table and let the adults talk..... :jester:
So... is it zeroed for 50 yards, or 200 yards?
https://media.tenor.com/u1V_-f-jXmcAAAAC/malreynolds-firefly.gif
Is that a real question? Seriously, I can't tell with some of the BS posted in this thread.
So... is it zeroed for 50 yards, or 200 yards?
https://media.tenor.com/u1V_-f-jXmcAAAAC/malreynolds-firefly.gif
What?
Defaultmp3
06-05-23, 09:23
Is that a real question? Seriously, I can't tell with some of the BS posted in this thread.Uh... yes, it's a real question. Did they zero for 50 yards, or did they zero for 200 yards? The crossovers might be relatively close for some gun/ammo combinations, but for some of my guns, with some ammo common ammos, it's over an MOA of elevation off at 200 yards if I zero for 50 yards. Depending on the precision you need, I'd consider a zero that is a whole MOA off to not be satisfactory.
Colt Carson
06-05-23, 13:38
I always thought your zero was where the bullet crossed the line of sight the second time, but I’m old school so who knows. One of my ARs has a 2.3x optic on it. When I wanted to sight it with a 200 yard zero, I first dialed it in to hit point of aim at 50 yards. Luckily when I moved the target out to 200 yards, I was almost dead on the bullseye.
Even if your shooting range is only 100 yards, you can still use a ballistic chart and sight your gun to hit one or two inches high at 100 yards. It’s always good to test at farther range, but it’s better than castrating the cartridge with a 100 yard zero.
If you zero at 50, then confirm at 200, if you have to make a correction at 200 you’ll likely still be very close to to zeroed at 50. The general idea for all of these zeros is to get on paper up close, then true it at distance.
The caveat to that rule I’ve always gone by is if I’m worried about wind drift, sometimes a closer range zero can actually be more precise. At 200 slow rounds like 7.62x39 will have some shift even in a fairly light wind, so depending on your environmentally you may want to just zero at 50 and call it good. I personally have a BDC or mil reticle in all my magnified optics, so I stick with a 100m zero and know the holds for that range.
ViniVidivici
06-05-23, 13:59
When we refer to which zero we're using we're generally referring to the FIRST distance at which the bullet crosses the LOS, or as with the 100yd zero, the ONLY spot where that happens.
Colt Carson
06-05-23, 14:13
Unless I happened to have an optic with a ballistic reticle (which I don’t), I feel the maximum point-blank range method of zeroing is superior vs getting hung up on a particular yardage for zero. What I’m saying is that a 50/200 yard zero is far superior to a 100 yard zero.
Colt Carson
06-05-23, 14:28
Personally, I like my bullet to stay within about 2 inches above line of sight…
https://thenewrifleman.com/maximum-bullet-flight-getting-the-most-out-of-ar15-zero/
ViniVidivici
06-05-23, 14:54
Unless I happened to have an optic with a ballistic reticle (which I don’t), I feel the maximum point-blank range method of zeroing is superior vs getting hung up on a particular yardage for zero. What I’m saying is that a 50/200 yard zero is far superior to a 100 yard zero.
You do what works best for YOU, in YOUR mission, that's what the rest of us do.
I too prefer the 50/200, for guns that're going to mostly be used at those distances. With 16" guns, I zero with my staple load (62gr FMJ loaded on the hot side) at 50 yards, and they're back to dead-on at around 225 yards. I still know where to hold for those out to 300 though.
Magnified optics get zeroed at 100yd, and the holds on the graduations of the reticle at various distances are identified and noted, through live-fire. This should be done even with a dedicated BDC of course.
The concept of the 100yd zero for every rifle DOES have much merit however, and has been discussed at length here.
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