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Old 04-24-2013, 13:50   #1
arnettjd10
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Puzzled on sighting in rifle

Ok I know how to sight in my AR. What I do not understand is why my friend that is in the army says he was taught that u should zero your rifle at 25 meters because then it will be dead on at 300 meters. The trajectory part of it makes complete since to me but at 25 meters the rifle could be off a fraction of an inch that wouldn't even be noticeable, but at 300 meters it would be several inches off. Is there something that I'm missing here?


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Old 04-24-2013, 14:08   #2
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You gotta zero somewhere, at some known calculation.

You are figuring out why a perfect close zero is so important. Off by a little close means being off by a lot far. Of course, if you have a 300M/Y range, go ahead and sight it in there. Then you should be on at around 25M/Y.
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Old 04-24-2013, 14:34   #3
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You gotta zero somewhere, at some known calculation.

You are figuring out why a perfect close zero is so important. Off by a little close means being off by a lot far. Of course, if you have a 300M/Y range, go ahead and sight it in there. Then you should be on at around 25M/Y.
Bingo. Most shooters won't see a difference worth much, though, since most won't be able to reliably hit a man size target at 300 anyway.

Personally, I prefer a 50 yard zero for irons and red dots, and 100 yard for calibrated magnified optics.

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Old 04-24-2013, 14:58   #4
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There is a BZO target. (Battle sight zero). IIRC it has a small circle over a square. Aim for the circle at 25 meters and put your impacts in the square and you will be close at 300 meters. Did it about 30 years ago in the Marines. Details are fuzzy but that might be idea of sight at 25, hit at 300 comes from.
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Old 04-24-2013, 15:36   #5
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a battle sight zero is just that, a battle zero not a precision target zero. the military has a method of calculating the hit probability of a man sized target so being off a little isnt bad for that purpose.

from a precision standpoint, 1MOA is only 1/4" at 25 yards and when considering you are shooting a bullet with a diameter of .224", it leaves very little room for error over a true single hole. in my experience, a 3 shot group covered by a quarter was acceptable and a dime was better but that is still about 2-3MOA at best, not exactly a precision rig.
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Old 04-24-2013, 20:30   #6
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Quote:
Originally Posted by arnettjd10 View Post
Ok I know how to sight in my AR. What I do not understand is why my friend that is in the army says he was taught that u should zero your rifle at 25 meters because then it will be dead on at 300 meters. The trajectory part of it makes complete since to me but at 25 meters the rifle could be off a fraction of an inch that wouldn't even be noticeable, but at 300 meters it would be several inches off. Is there something that I'm missing here?


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Because of the height of the sights on an AR above the bore, there will be two points of impact at your point of aim along the trajectory of the billet, except for the 100 yard zero in which the bullet is always below the point of aim except right at 100 yards. Most commonly people use either the 25/300 zero or the 50/200 zero. The most important number here is the second number. Alway zero at the longest distance. A 25 yard or meter zero is not a 300 yard/meter zero, but it may be close. A 300 yard/meter zero will be pretty dawg gone close at 25 yards .
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Old 04-25-2013, 03:17   #7
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Don't get me wrong i understand why people want to sight in for 300yds/meters.. but
if this is a home defense firearm... where are you at 10ft?? thats just something
to think about

I did the same thing as a MARINE... but we knew that it was just to get us started
then you would dial it in once you got it on paper..
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Old 04-25-2013, 04:15   #8
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With either a 25/300 or 50/200 zero, you will have a 2" vertical offset at less than 5m. Aim for his neck, you'll put them in his ribcage. Or, aim for his nipples and put them in the gut.

Either way inside 25m, a hit is a hit, though it might be a bit low.
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Old 04-25-2013, 06:31   #9
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If you don't practice it, you won't know and if you need
a precise shot... a hit anywhere isn't a hit...

Case in point> a head shot around the corner of a hallway..
i'm not trying to be a smartazz, but if you don't know where
your hits are going to land inside of a home... then IMO
you are just praying and spraying.... again just my .02
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Old 04-25-2013, 13:03   #10
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For me, zeroing was one of the most confusing and frustrating things when I started shooting (and it's something I still refer to books and write-ups for any time I do it).

Think of the zero of a rifle as a "base" from which all of your shots will come from. Unless you only shoot at your zero distance, you'll have to rely on hold-overs or hold-unders for good accuracy. I first tried the 25 meter zero. This worked well since the local indoor range only went to 25 meters, and I figured all my defensive shooting would be at 25 meters or less anyway (typical dumb noob mistake).

After a while, I was shown the light of why the 25/350 (and 300 meter) is a pretty bad zero. So I switched to the 50 yard zero, which I think is a fine zero. This allows for hits in a 4" area out to 250 yards or so.

I've recently come to prefer the 100 meter zero for it's practicality at reasonable ranges for the AR-15. I use this (and the 50 yard) to make shots on silhouette targets out to 300 yards now pretty easily. With the 100 meter zero, I never have to worry about my round going higher than my point of aim, either.

So my recommendation is forget the 300 meter/yard zero and go with either a 50 yard or 100 meter.

To your original question, zeroing at 25 meters does not give you a 300 meter zero. It gives you a 25 meter zero. Your zero isn't a true zero until it is shot at distance. Shooting first at 25 will get you on paper at 300, but you'll still have to adjust once there.

Lastly, all of my numbers will vary slightly due to differences in barrel length, and bullet.
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Old 04-25-2013, 13:25   #11
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Well said..... we try to practice all shots within a "Home size area"
100yd shots are for fun and in-case the Zombie come calling LOL..

Don't get me wrong i love distance shooting, but i have to come
back to the real world after awhile... LOL.. again good reply

Last edited by Drako28; 04-25-2013 at 13:29..
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Old 04-25-2013, 13:34   #12
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Well said..... we try to practice all shots within a "Home size area"
That is something else. Knowing your hold-over for 0-25 meter shooting absolutely key. It's great to say that hitting under by 2" is okay and will still put you center of mass, but you won't always have a perfect silhouette to shoot at. I think this is echoing what you said earlier. Basically, practice is key.
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Old 04-25-2013, 13:37   #13
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Well if your going to use your AR for strickly CQB then site in for that distance! Whats the big deal! With a 25 meter site in you be 2" low at 10 meters - for a head shot aim between the eyes hit just under the nose- dead perp!
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Old 04-25-2013, 14:06   #14
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Quote:
Originally Posted by arnettjd10 View Post
Ok I know how to sight in my AR. What I do not understand is why my friend that is in the army says he was taught that u should zero your rifle at 25 meters because then it will be dead on at 300 meters. The trajectory part of it makes complete since to me but at 25 meters the rifle could be off a fraction of an inch that wouldn't even be noticeable, but at 300 meters it would be several inches off. Is there something that I'm missing here?


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I personally go w/ the 50/200, but either way, zero at the closer distance and CONFIRM at the longer distance. Make any adjustments as needed.
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Old 04-25-2013, 15:01   #15
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Drako28
Well if your going to use your AR for strickly CQB then site in for that distance! Whats the big deal! With a 25 meter site in you be 2" low at 10 meters - for a head shot aim between the eyes hit just under the nose- dead perp!
This is how I used to think and now I realize it is kind of foolish. Even if your primary use for your rifle is home defense, you're still going to want to learn to use the rifle at different distances. Setting a 25 meter zero does both the shooter and the rifle a disservice and prevents them from reaching their full potential.
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Old 04-25-2013, 19:11   #16
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Thank you for responding, i couldnt have said it better... i shoot from all distances heck
we practice at arm length while backing up... IN the dark!!! try that with a moving target
coming towards you and your hair on your neck will raise up...LOL..

Listen guys/gals all i'm saying is what works for ME... i'm always up for change, but i tend
to listen to people that have been in the middle of a firefight and know what works and
what will get you killed..

Trust me when you put yourself in a stressful events almost everything goes out the
window... You will always fall back to the BEST training you have done... and if you
have to think about it... more then likely that's enough time for the Bad guy to do
harm... again this just my .02 cents... good luck all and great debate...
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Old 04-26-2013, 13:34   #17
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Thats only if you become stressed! When you train situations become less stressful! Maybe it's just me but I don't get stressed under those type situations I become cold and unfeeling- focused!
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Old 04-26-2013, 14:37   #18
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The US military style of zeroing the sights for the M16/M4 family is; as others already mentioned, called "battlesight zero". It's based on the "point blank range " concept.

With the ballistics of the typical military 5.56mm ammo, that means adjusting to hit at the battlesight zero target set at 25-m. Then you can put your sight on center mass between 0-m and 300-m, and it should hit more or less on the torso area.

Point blank range concept is not to be confused with "grazing fire", which is a different animal altogether.
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Old 04-26-2013, 16:14   #19
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Gunnut> You are right to a point!! I also don't become stress and function clearer
thru drills... But!! that isnt the norm and people will always fall back to the degree of
training they had.. You also need to train Alot to get to that level... I taught self defense
for many years and the weekend warriors IMHO were SOL when the SHTF... You can read
books watch videos and even take some classes, but unless
you are training on a regular basic and getting your muscle
to remember on their own without thinking... sorry but
i have to disagree and say MOST people will hesitate and that
enough to get them killed..

This isnt something i read we have actually press
people to see what would happen...

Also remember training under stress is good, but it will never
match the real thing.... You will fall back to the
deagree of your training...and again i will remind you
that this is only my .02 cents...

Last edited by Drako28; 04-26-2013 at 16:15..
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Old 04-26-2013, 23:38   #20
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The difference is going into a situation vs finding yourself in a situation. In CQB you have a plan, assigned tasks, known objectives! Clearing your home is the same thing- you know your home -most likely better then the intruder. You either engage or draw your perp(s) to the place where you are in command of the terf. Or push them to your kill zone.
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