AR zero distance picture 1

Zero Distance for a Home-Defense AR-15

A former SOF Sniper explains where to zero your AR for home defense, and more importantly, why.

By Kenan Flasowski (RSS)
April 10, 2012

AR-15-style carbines are the most popular long arms in America these days, and many people are buying or building their own for competition, hunting, varmint control and more often than not, self-defense. While many folks invest in professional instruction on how to operate and employ their new carbine, others wish to go it alone and train independently or with friends and family. A common question for new AR owners and even some more experienced shooters is, at what distance should the AR-style carbine be zeroed? To avoid any confusion, the term “zero” means the point at which the path of the bullet intersects with the shooter’s line of sight (LOS).

My intent is to provide the “80-percent solution” for people who may have limited range facilities and are concerned about placing accurate fire on bi-pedal mammals of the outlaw variety. Also, I am totally committed to keeping things as simple as possible when planning for encounters with an armed threat in your own home or on your property.

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The Long Answer

The long answer is (as usual), “that depends.” What does it depend on? A number of factors: Intended use, type of sight, caliber, type of ammo and barrel length, to name a few.

For our purposes, let’s keep it to the following specifications: The carbine itself is chambered in 5.56 NATO/.223 Rem. with a 16-inch barrel. The sighting device is a non-magnified red-dot/reflex sight, as such units are most appropriate for short-range, CQB-type shooting—engaging targets quickly while under duress. Ammunition will be limited to 55-grain and 62-grain FMJ loads, as they are the most prevalent. The intended use of the carbine is for home and self-defense in an urban environment for target distances of less than 200 yards, particularly less than 20 yards.

We also need to establish what an acceptable level of accuracy is for human targets within 200 yards of the shooter. In most cases, placing rounds within 3 MOA should be sufficient. This equates to all rounds impacting within 6 inches at 200 yards, 3 inches at 100 yards and less than 2 inches at 50 yards.

Two terms we need to understand are “holdover” and “holdunder.” The first refers to the act of placing the point of aim (POA)—red dot, crosshairs, front sight, etc.—ABOVE the place where you want the bullet to go. The second is just the opposite, aiming BELOW where you want the bullets to go.

I have to stress one factor that all AR owners must understand and accept: The effect of the height of the sights/optic above the bore of the AR-style carbine mandates using holdovers REGARDLESS OF ZERO. Most flattop ARs will have a sight height of between 2.5 and 3 inches (depending on the mount) if using an optical sight. If you mount an optic on the carrying handle, it will be even greater. This results in the shooter needing to apply holdover when engaging targets at close range, i.e. inside a house or other structure, at distances of one to 20 yards. This holdover increases as the distance to the target decreases. At 25 yards, the holdover is about 1.5 inches, incrementally increasing to the sight height at about 7 yards and closer. This means if you want to put a bullet into the eye/nose area of a person holding a knife to a loved one’s throat at a distance of 4 yards, you need to put the red dot at the hairline, or roughly 2 to 3 inches above the eyebrows.

The Short Answer

The short answer to the “At what distance do I zero?” question is, in my opinion, 100 yards (or meters). Here’s why: The bullet should never rise above the LOS. This means the shooter does not need to use holdunder at any range, eliminating that factor and leaving only holdover as a matter of concern. The amount of holdover needed to meet the aforementioned level of accuracy is very small with a 100-yard zero—approximately 2.5 inches at 200 yards, .5 inch at 150 yards, and .75 inch at 50 yards. On most ARs using 55-grain or 62-grain ammunition, the bullet is generally never more than 3 inches below LOS until the target is beyond 210 yards. For most of us, this means that to hit a man in the chest out to 150 yards, we do not need to hold over. You can’t get any simpler than that.

The bottom line: if we have a rifle/ammo combo that shoots 3 MOA or better accuracy and we do not apply any holdover at a 150-yard target, the lowest round from the resulting 4.5-inch group should be no more than 3 inches below the “X.” Good enough. For engagements inside your home, at distances inside of 20 yards, you can use a consistent 2.5-inch holdover and still make acceptably accurate head shots.

What Does it All Mean?

But this AR is for self-defense inside a house. Why zero at 100 yards when the biggest room in my home is not even 10 yards? Some people may consider zeroing the carbine at a very short distance, say 15 yards, using the logic that inside their home they will never engage anything farther than that given a likely self-defense distance of less than 7 yards. That may be true, but the negative results of a 15-yard zero become obvious when examining the bullet’s path at distances greater than 20 yards, and realizing that a holdover will still need to be used at shorter distances.

With a 15-yard zero, the bad news is at 10 yards the bullet is about an inch low, and at 5 yards it is about 2 inches low. You will still need to apply holdover to make a good headshot on the bad guy you meet coming into your bedroom. The really bad news is that at 25 yards, the bullet is almost 2 inches HIGH. At 50 yards it’s about 6 inches ABOVE LOS and at 75 yards it’s 10 inches HIGH. When you hit 100 yards, the shooter would need to aim almost 14 inches BELOW the desired point of impact, so if you ever need to make a shot outside the home, well, let’s just say that’s a lot to remember in a life-threatening situation.

Some may ask “What about the 25-meter zero that I used in the Army with an M16A2?” That was determined to be optimum by the Regular Army using a 20-inch barrel and M855 62-grain ammo. It has a holdunder of about 6 inches at 100 yards and 9 inches at 200 yards, which is ultimately just more you have to remember.

Another good option is the 50/200 zero. I am a big fan of the 200-yard zero, and it is very close to a 50-yard zero. My primary AR is zeroed at 200 yards, but I like to be able to engage out to the maximum effective range of the 5.56 NATO cartridge. With a 200-yard zero, the bullet does rise above LOS, but not more than about 2 inches at 120 yards, so holdunders are negligible, and the holdovers at 25 yards and closer are similar to the 100-yard zero. But I have the luxury of unlimited access to a 400-yard range. Many armed citizens may not get to train much and may not shoot at 400 yards—ever.

You have probably noticed by now that words like “approximately” and “about” are used frequently when stating the distance between the bullet’s path and the shooter’s LOS. This is because every carbine/ammo/sight combination will be a little different.

If at all possible, use a 100-yard/meter range to confirm zero. That is the only way to be sure. If all you can use is a 25-yard range, then the center of the group should be 1.5 inches below POA. I strongly recommend firing groups of at least 10 rounds when zeroing. Most of us make a slight error every now and then when shooting, especially during the zero process, and shooting smaller numbers of rounds per group will be affected by these errors. If you make a couple of bad shots in a five-round string, you now have 40 percent of your shots (two out of five) off POA due to shooter error. With a 10-shot group, the error rate drops to 20 percent (two of ten), so you can call one a “flyer” and blame the other on poor quality control. Then, adjust from the center of eight good shots.

Ultimately, if you have an AR for home defense, get a good, solid, 100-yard zero for your sights or optic. When the time comes, hold dead-on outside the house and a couple of inches high if you are inside. Simple enough.

Bullet Path Relative to LOS Using Different Zero Ranges

Target Distance 15-yard zero 25-yard zero 50-yard zero 100-yard zero 200-yard zero
5 yd -1.8 -2.1 -2.4 -2.5 -2.4
10 yd -0.9 -1.6 -2.1 -2.2 -2.1
25 yd +1.8 0.0 -1.2 -1.6 -1.4
50 yd +5.9 +2.4 0.0 -0.8 -0.3
100 yd +13.4 +6.5 +1.6 0.0 +1.1
150 yd +20 +9.4 +2.1 -0.4 +1.2
200 yd +25 +11 +1.1 -2.1 0.0

Data is an average based on information from several ballistic software programs and the author’s field experience.

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Comments

45 Responses to Zero Distance for a Home-Defense AR-15

  1. Lee says:

    Good article, Kenan. I have been teaching the 100 yard zero for several years in police patrol rifle classes!

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  3. I don’t get it. The author says…

    “This means the shooter does not need to use holdunder at any range, eliminating that factor and leaving only holdover as a matter of concern.”

    Outside of extremely short ranges and long ranges outside of consideration for civilian home defense, why would you bother worrying about holdover/holdunder?

    The whole point of a 200 yard zero is to eliminate having to worry about bullet trajectory. At any range between muzzle and 250 yards or so, the bullet will always impact within 2.5 inches high or low. Stick the red dot on the target’s center of mass and worry more about proper trigger squeeze than you do about bullet trajectory.

    Only at extremely short range when shooting at small targets (like a head) do you really care about the fact that the bullet is going to impact low. So for hallway length shots, aim a bit high.

    If you use an EoTech, instead of an Aimpoint, the bottom of the circle is the 7 yard zero point anyway. So slap the bottom of the circle between the intruder’s eyes and (again) worry more about the trigger than the bullet.

  4. Pingback: Good article on Zero distance for a home defense AR15!

  5. Karl says:

    Not looking to start a ood fight here, but…M-14/Mini-14 iron sights are considerably closer to the bore as are iron sights on lever actions. You still have to make these calculations but keeping the LOS closer to the bore is easier with some other rifles.

    • Brad says:

      Karl, read the name of the article, its Zero Distance for a Home-Defense AR-15. At no time was the mini 14 mentioned and yet you comment on it. Try reading before posting, you just may learn something

      • Karl says:

        Yep. Learned that sight height on ARs is a problem to be dealt with at short range. Lower mounted sights greatly reduce the issue. As familiar as I am with the M16 series, I can’t bring myself to buy an AR.

  6. Mike says:

    use an ak much more efective doesnt realy matter what you hit its done.

  7. ::G says:

    “The bullet should never rise above the LOS.”

    This is a bit picky, but with any “zero”, the bullet will always cross the line-of-sight at two points, e.g. 50yds/200yds. From the rest of the text, I think you meant that the rise will be smaller with a 100yd zero than, say, a 25m/300m zero, so you can effectively ignore it on a badguy-sized target. Even so, between the two places where the LOS is crossed, the bullet will definitely be higher.

  8. Daniel Z says:

    From the data table, Sorrentino’s point could be extended to any range from 50 yards.

  9. new guy says:

    My EOTECH has a 3″ offset by my measure. I landed on th e 200 yard zero for the exact reasons you mention here. Now I feel better about it. At the ranges I go to, I can shoot from 25 yards, 50 yards, and 130 yards so I have to use the table which I plan on printing out.

  10. Marie says:

    As an attorney, I think you would have to be in a very unusual situation to successfully argue self-defense if the bad guy was two football fields away from you. Be sure to check your state’s self-defense laws WAY before you act.

    • jeff says:

      as a soldier , I think that if your being shot at a measly 200 yards is not enough distance to safely exit the situation with out return fire :) . its all perspective, not all ” bad guys” are home intruders. I forgot though as an attorney, who I assume thinks the system works well. your cant see outside the box of your commietopia . some citizens are prepared to defend America. Some are cattle.

      • Grey Wolf says:

        ” I forgot though as an attorney, who I assume thinks the system works well. your cant see outside the box of your commietopia . some citizens are prepared to defend America. Some are cattle”

        I needed a good laugh Jeff, Well Done! From one Soldier to another Well Done!

      • James says:

        That’s right, die on your feet instead of living on your knees!

    • George says:

      200 yards goes beyond just home defense. This also applies to property defense. While most people may not live on a couple acres, some people do. By including this, the author was able to make this information pertinent to everyone who would read this article, including those of us who use an AR-15 for protecting livestock.

  11. Interesting comments, and I would like to address a couple of them – first, to correct “G” – the path of the bullet does not always cross the line of sight – the angle of the barrel in relation to the LOS on any firearm can be adjusted so the highest point of the tragectory is at LOS at just one point – granted, most firearms are adjusted so that the bullet path crosses LOS twice, as with the 50/200 and 25/300 zero for M4 and M16s.

    Second, for Mr Sorrentino, yes I do care that the bullet will impact low at short range – especially if the bad guy is hiding behind a family member or is behind cover and I need to make a precision shot. And I sincerely hope that my local Law Enforcement officers know exactly what their holds are in case they have to come to the aid of my family or friends. And there are many more optics in use than just Aimpoints and EOTechs, and a ton of different dots/reticles. Not everyone is going to drop $500 or more for an optic, even though I believe the quality is worth it.

    Third, the term “homeowner” applies to those of us in rural areas too, not just urbanites. Many AR owners describe their homestead in terms of acres, not square feet, so having to make a shot from the house to the barn is a possibility. A 150 yd shot for a coyote or hog is not unreasonable.

    Lastly, the target audience of this article is newer AR owners and those without formal training from a reputable source. Everybody else has already decided on a zero-distance and hopefully confirms it regularly.

    Thank you for your time.

  12. Ed says:

    This lesson could help a person skip many hours of self-teaching and save a lot of ammunition/money. Thank you.

    Keeping a carbine for home defense should probably dictate a semi-dedicated setup. By this I mean getting the optic of choice as close to the center line of the barrel as possible, keeping the LOP at a comfortable and appropriate length, and practicing enough to create the muscle memory and to teach your brain to do something that may seem counter-intuitive.

    I believe that keeping one rig to shoot between 5 yards and 400 yards is putting a heavy burden on the shooter to practice until it’s comfortable and consistent. A reflex sight is great for the shorter distances, but most will quickly reach an acceptable limit, with regards to accuracy and consistency. Magnification for greater distances then becomes necessary.

    Those choosing to use an AR for home defense most likely don’t have the resources for what some might consider a more appropriate close quarters rig, like a handgun. Fortunately, some of this lesson applies to learning the nuances of using a handgun with laser sights too.

  13. Jeremy says:

    Do you have this same kind of Table for .308/7.62X51? I Know .308 is considered a risk for over penetration in home defense, but it’s what I have and I intend to load the Winchester 120gr personal defense round when the gun is in the home.

  14. William says:

    Sorry if this is a stupid question but I didn’t notice it in your very informative article. With an EOTech and BUIS, are both being set to the same zero? There are some who have them set differently. Thanks for your time in advance.

  15. William, some may zero irons and optic at different distances, but I have always had them zeroed at the same range. Same holds no matter what distance the target is.

  16. Jeremy,

    If you go to the JBM Ballistics site, there is a program that can calculate the .308 tables for you, or get one of the smartphone apps like KAC BulletflightM, MD ballistics, or iSnipe.

  17. Scott Robinson says:

    While I respect everyones right to their opinion here, I also believe that some people have earned their opinion while others simply feel they are entitled, and that more weight should be lent to opinions based on experince. I have read as some of you have challenged the authors opinion, which prompts me to ask some questions. Have you served in the military? If so did you retire from same? If so did you serve in the military’s premier Special Operations Force? Has your opinion been tested in thousands of hours of training, shooting, and numerous combat deployments? If not you might want to reconsider questioning this author, because he has done done all of these things. In my limited experience (both military & LE), as compared to the authors, VERY few have earned their opinion the way Mr. Flasowski has. So while you may have an opinion please ask youself if that opinion is based on years of real world operational experience or years of target practice and theory.

    • Eric Hawes says:

      Scott, that was poetic! Love your post. Exactly what I was thinking when I was reading some of the other posts. In my 14 years of military experience I have learned many things, one of them being: when someone of this caliber is teaching me weapons, I pay attention and don’t question the small stuff. If he’s using what he preaches, it’s being taught for a reason-It works!

    • Larry says:

      Very well thought out. One question though – does that all apply to the guys working in NASA’s Mission Control? I don’t think that they (at least most of them) have been in orbit – much less done so for hours and hours – nor did they retire from some previous Space program.
      Just sayin’ . . . . . . . .

      • Eric says:

        Many in NASA MC actually are former experienced astronauts. Those that aren’t are the experts in their respective field and are trying to teach a pilot how to be a scientist, engineer, astronomer, etc.
        That said, the prior advice stands: when an expert is giving advice, shut up and take notes.

  18. jeremy says:

    good advice for sure

  19. I just got back from the range with my AR. I am new to this & have only shot my Ar 3x. I zeroed in at 25 yards & started shooting at a 100 yard target after. All of my shots were high. I was starting to wonder if it was me or the gun which was the problem. Now I know & have some info. for the next time I go out. I will zero it in at 100 yards & see how it will shoot. Found this very helpful. Thanks!

  20. John Kay says:

    Kenan- great article as a US Marine and a long range precision rifle competitor I think your article is excellent. I am looking for a simple easy to understand description of the process for a civilian friend of mine that just got an AR and is trying to set it up properly. Unfortunately he is in one state I am in another.

    I’ll refer him to this page for sure. I am always amazed at how many folks who have never shot a round in anger tend to over think, over analyze topics like this. It is so simple yet it invites so much static by those who have read something somewhere.

    My advice is simple, either take this instruction to heart or don’t. But it is good advice and instruction.

  21. ED says:

    Great Write up.AR15 Carbine, 5.56 NATO/.223 Rem information Charts explained.

  22. chad says:

    i have a 16 inch barrel and an aimpoint with 1/3 co-witness–i was told to zero at 200 yds by putting the red dot on target at 25 yds, but poi 2 inches low–would that be a correct 200yd zero–or very close?

  23. Adam says:

    If using the government standard zero sighting target at 25m for 300m with a 16 inch barrel and 55 grain ammunition, how much lower should the grouping be if I wanted to sight in for 200m?

  24. Chesty Puller says:

    The AR-15 is not a reasonable home defense weapon to begin with. Take it from someone who has been multiple engagements with insurgents in close-quarters. A shotgun us a much better choice in a country where our walls are made of gypsum board. Loaded with the proper ammunition, over penetration of walls is not much of an issue and it still packs enough hydrostatic shock to effectively put fuckers down. The AR-15 for civilian use is a fuck around and varmint hunting gun, not a personal defense weapon. Then again, someone who doesn’t know the proper BZO procedures for a certain weapon probably is informed enough to effectively employ a weapon system to its proper potential. Give anyone a gun magazine and automatically they’re an expert.

  25. Jason says:

    So if I take a 25yd target and hit dead center with my aim point pro I can expect the filling results based on your chart??

  26. Lee says:

    Actually Jason you should hold center and adjust point of impact to 1.5 inches to 2 inches low at 25 yards, depending on the height of your aimpoint pro, if you are zeroing for 100 yards. That is what the article says. I have shot with Kenan and what he teaches works!

  27. Bill Stroud says:

    This is an excellent article. Thank you for your effort. It will be 100 yards for me!

  28. Rob says:

    Great post. It is critical for inexperienced users to understand the versatile ballistics of the .223/556 round.The 100 and 200 yard zero are both excellent. The user simply needs to determine which suits their needs based on most likely range of any anticipated shot. The bottom line is even with a 200 yard zero any CQB encounter will be multiple rounds and 2 inches low aiming center of mass simply doesn’t matter. If you aren’t an experienced Military or LE operator, head shots in a critical situation should not be contemplated. Remember the vast majority of Military and LE are NOT proficient marksman.

    CHESTY PULLER you simply do not know what you are talking about. The technology in a properly selected .223 round ensures it transfers a maximum amount of energy into a target very quickly resulting in ideal penetration. In contrast 9 .33 caliber pellets of 00 bunch do not. They are the equivalent of 9 rounds of ball ammo. 00 Buck will penetrate multiple framed sheet rock walls as will most pistol ammo. A BTHP .223 MAY penetrate ONE! There are many tests which illustrate this fact.

    • derek says:

      Well said. There is a reason that military and law enforcement generally opt for an AR variant over a shotgun for indoor engagements. Having learned to shoot the m16 in the Marine Corps, and carriwd a patrol rifle for a number of years as a police officer, I keep an AR next to the bed. And I live in an apartment with my family of five.

  29. WNCgun says:

    What do you all think of the military 36 yard zero with a 2.6 sight height this equates to -.7″ at 25 .9 at 50 yards 3.4 at 100 5.1 at 200 1.4 at 300 yards and about 0 at 300 meters. V.S the 100 yard zero which is -1.6 at 25 -.8 at 50, 0 at 100 -1.6 at 200 and -8.7 at 300. the 36 yard zero is easier for those that don’t have access to 100 yard range and is pretty decent within close ranges and gives better results for that 300 yard shot. I’m not sure how the 36 yard zero does at ranges closer than 25 yards but as to my knowledge it can not be more than -2.6 (the sight height). Also I’m not sure the AR should be promoted as a home defense weapon given its tendency to over penetrate at close ranges. If protecting you loved ones is a concern I’d recommend a shotgun for home defense as it is less likely to go through many walls and hit an innocent bystander. that said as a SHTF choice the AR is great choice.

  30. WNCgun says:

    Oh yeah this is a really helpful tool when trying to determine optimal zero range for your intended use. http://www.hornady.com/ballistics-resource/ballistics-calculator

    I actually Zero at 30 yards grouping 1/3 inch low to simulate 36 yard zero, due to having a bench rest at 30 yards at my home range. I have a couple 50 yard shots i can take at my home but from less stable positions.

  31. Bob says:

    Excellent article! As a new AR-15 owner, this will be very helpful.

    I would like to comment on some of the other comments here. In my opinion, the thread became side-tracked with the issue of expertise. I know that it irritates me when I read advice by people who have no idea what they are talking about in my specific area of expertise but I don’t think the criticism of non-experts is justified here. Why? Because sighting in is, for the most part, objective, not subjective. The truth is in the ballistic tables. This is one case where it makes little difference whether someone is highly experienced or has very little experience. The ballistic tables tell it all and, if used properly, the shooter can see for himself or herself what he best zeroing distance should be for their particular needs. In fact, someone who has almost no (or even no!) experience shooting could look at the ballistic tables and determine what zeroing distance makes most sense for a particular application. Of course, there are other things where an expert’s advice is much more valuable than that of someone without much experience but this isn’t one of them. For example, the issue of what weapon is best for home defense has lots of room for subjective opinion and that’s a case where the opinion of a highly experienced person is very valuable.

    Again, the ballistic tables tell it all. The author of this article made an excellent argument for sighting in at 100 yards and the data confirms what he says. But anyone could have looked at those tables and come to the same conclusion. We are talking about objective data here. I can tell the temperature just as well a PhD. in meteorology. To do so, all I have to do is look at an accurate thermometer and, in the case of the subject of this article, all I have to do is look at the ballistics tables.

  32. kxdan01 says:

    Thanks for the great information, THIS IS EXACTLY WHAT I’VE BEEN NEEDING TO SEE REGARDING SIGHTING IN MY AR, THANKS FOR THIS GREAT 100 YARD ZERO OPTION. You guys may want to consider buying a budget shotgun, you cab get a nice 12 Gauge Shotgun with a 18′-20′ Barrel for $200 or less- check out the Maverick 88 which is exactly like a Mossberg 500, Rock Island Armory has a M5 for $250 or less. Pick up a nice quality Pistol too like a Glock, XD, Sig-Sauer, M&P, or nice .357 Magnum Revolver, no cheap pocket gun junk, small guns are very unreliable especially late model Taurus, Kel Tec .380/9mm and Similar.never buy any HI-POINT- Period! you get what you pay for with guns

  33. Rick says:

    Good article. But again many factors that should be considered. This is from a tactical LE point of view.. AR-15 as a short range in urban combat rifle. Application is everything. If you are working in primarily 15 yards and in a 15 yard zero makes sense. Why? The term CRITICAL shot. That’s why. A critical shot is a shot taken under EXTREME stress with a possible hostage in play. Point of aim point of impact matters. Knowing and being able to consistently control with extreme accuracy your hold over is paramount in taking a critical shot. You decide which works best for you in extreme situations. Option: Zero your irons to 50/200 for those situations that require a distance shot. Just one perspective…

  34. Thomas says:

    The data on a 50-yard zero does indeed look good.

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