Zeroing question re: same point of impact at two distances.

[Deer_KiLLer]

I can't believe that no one has pointed out that the iron sights on an AR have this convenient feature built right into them: they have an elevation knob at the base of the sight that's marked in easy-to-read increments that allows you to zero the rifle at 25m, and then adjust the rear sight for any known distance (or even for any guessed distance).

YMMV.

[/

ahh that thing doesnt work. useless junk... just turn it till you hit the target and then leave it alone LOL....

 

[Deer_KiLLer]

http://ar15zeroing.com/

http://www.ar15.com/content/guides/sightIn/

http://www.americanrifleman.org/Video.aspx?vid=1881

 

[center442]

The factor that varies with the type of sight is limited to the height of the sightline over the muzzle. If that remains the same, then the calculations are valid regardless of the type of sight employed.

50/200 works fine with an Eotech.

Thanks for the info, guys.

 

[Deer_KiLLer]

I had a friend ask, so why do I need a ballistic chart for?

so I figure ill answer it here also just in case so that anyone new to this subject and wondering why?

on an AR... most the iron sights are like ballistic tuned turrets designed to work with a "battlefield zero" if all works perfect if you sight in your battlefield zero all the other adjustments should work. number of things could affect this but it can be fixed on the range by simply shooting it and seeing what it does, should try it out anyway if possible just to see how it works... maybe a little turn of the front sight here and there to better tune you rear sights ballistic adjustments along the way... so every time you change ammo the ballistics change your zero changes.

an example for sighting in a deer rifle using the same great idea, regular scope no ballistic turret but you want to get the most out of your zero using this idea..

IM going to use a .308... using these online ballistic...

I can keep putting in different ranges for my .308 load until I get a zero I like...

lets say you choose a 200 yard zero for it... the ballistic chart is a map on how to get there. of course the better the map the better you get to where your going but a map is a map. it tells you where your bullet should be at each range.

you have this chart might not be perfect but it doesn’t have to be its going to tell you your goal... keep in mind it might not be perfect due to reasons like sight height etc. and maybe you need to be 1.5" high at 100 not 1" or your point blank zero distance should be 28 yards not 25. little sht that ounce you shoot it at 200 you’ll see if your a little low or high a lot easier than you can at 25 yards. the end result is the ballistic chart got you on target.

yes after a while you can see some ballistic charts are better than others. most charts are just standard. 1.5 sight height, 20something inch test barrel.. a chart where you put in your own data, sight height, barrel length, rifle twist is going to be allot more accurate of course.

 

[arlow]

50 yards is -1/2 of your 100 yard zero.. if your 1" high at 100 your 1/2" high at 50 for an example.. but if your an unseen 1/4 high at 50 your 1/2" high at 100.

Not if line of sight is 1" above bore because for the bullet to get to 1/2 inch high at 50 then the bullet actually needs to rise 1.5 inches to that point which then in turn puts the bullet closer to 3" high at 100

 

[Deer_KiLLer]

Not if line of sight is 1" above bore because for the bullet to get to 1/2 inch high at 50 then the bullet actually needs to rise 1.5 inches to that point which then in turn puts the bullet closer to 3" high at 100

yea thats correct... i just tossed out numbers on that one.. sight hight will change things..

but one things for shure to get 50 yards to = 100 yards you would need a sight hight thats number would look something like PIE i would think. a 1/4" 1" 3" etc might not look differant at the two distances but add 300 yards and the differance is a hit or miss

i see more people sight an AR in at 50 and shoot clear over the target at 100.. i think they sight in high thinking its going to drop at 100.. it doesn't drop.

 

[Admin]

i see more people sight an AR in at 50 and shoot clear over the target at 100.. i think they sight in high thinking its going to drop at 100.. it doesn't drop.

Who are you shooting with Stevie Wonder, Hellen Keller, Andrea Bocelli, and Mike Seeklander?

 

[Jose]

LOL!!!!

I remember shooting some highpower practice at a public DNR range in Kansas during hunter sight in days. Some of those guys were freaking train wrecks.

 

[EddieCoyle]

LOL!!!!

I remember shooting some highpower practice at a public DNR range in Kansas during hunter sight in days. Some of those guys were freaking train wrecks.

I was at my local range when a Fudd was sighting in a rifle to take on a hunt with him in PA the next day. He was getting all pissed off because instead of the shots moving up on the target, they were moving to the left when he adjusted his scope.

Yup. He had the scope turned 90 degrees.

 

[jasons]

Another +1 for the Santose method. It will will get you within 2 or 3 inches of point of aim with any common ammo and at any distance up to 250 meters or so. That's more accurate than I am, especially with a carbine. (Not that I'm even close to high master or anything...)

 

[Deer_KiLLer]

I was at my local range when a Fudd was sighting in a rifle to take on a hunt with him in PA the next day. He was getting all pissed off because instead of the shots moving up on the target, they were moving to the left when he adjusted his scope.

Yup. He had the scope turned 90 degrees.

we had this guy hunting with us, brandy new swaro scope... oh course i asked why it was right side left, he said its german and thats the way they are

he missed 3 deer, 2 of them he admited to missing...

so he was in back of the hunting camp with his buddy blasting away trying to sight it in. a trip to walmart for more ammo and back to blasting. well they came in the shack and said your a good shot can you sight my rifle i felt bad so i said ill sight it you test it after.. i grabbed some tools you know and was going to fix the scope first... OH NO no that was installed by a profestional gunsmith so he wouldnt let me fix it...

well i took a shot... locked the rifle down and put the cross hairs on center and dialed it to the where the dust cloud was wrong at first but i changer direction and got it to the dirt spot. took 2 shots, on paper! dialed it again wrong at first again but after i saw the cross hairs move the wrong way here and there, i just change direction and dialed right to the 2 shot group. took 2 shots dead center, then i got stuck for a min trying to figure out was left up or right up, figured it out because i dialed it to be an 1" high at 100 and took 5 shots. close enofe good enofe..

he shot it and hit the target and thanked me...

he missed a deer, went back to the range and messed it all up.

 

[PatMcD]

Who are you shooting with Stevie Wonder, Hellen Keller, Andrea Bocelli, and Mike Seeklander?

ZING!

 

[FPrice]

Well, I adjusted my rear sight per the Santose method today. Hopefully I'll be able to get to the range this week and get my fifty-yard zero. I will be able to check the 200 yard impact since we have a berm at about 210-215 yards also.

 

[deadhead133]

Who are you shooting with Stevie Wonder, Hellen Keller, Andrea Bocelli, and Mike Seeklander?

Andrea Bocelli........Gotta love it!

 

[FPrice]

I finally found the article I was looking for. It was in the Oct 2008 issue of SWAT Magazine. It compared the Army's 25/300 meter BZO, the USMC 36/300 yard version, a 50/200 yard zero, and a 100 yard zero. The article also provides a good graphical demonstration of the bullet rise and drop from muzzle out to 500 yards (meters for the US Army). The article also discusses the mechanical errors in switching apertures on the AR-15. It's an interesting read.

http://www.swatmagazine.com/archive_2008/oct08.php

 

[FPrice]

Another question

I am beginning to sight in an M-4 style carbine, flat top with the standard AR front sight and a removable rear sight (no carry handle).

The rear sight does not have room to adjust the elavation drum down to contact the base as does the stadard A2 sight. Will a 50 yard zero still accomplish the same 50/200 yard zero as the Santose method?

 

[Jose]

The rear sight does not have room to adjust the elavation drum down to contact the base as does the stadard A2 sight. Will a 50 yard zero still accomplish the same 50/200 yard zero as the Santose method?

Outside of sight height above bore centerline, the type of sight you have is completely irrelevant to the bullet's trajectory.

Zero at 50 yards with common 5.56 ammo and the bullet will be back down to the line of sight at 200 +/- 20 yards.

This is simple stuff.........

 

[bullseye]

Outside of sight height above bore centerline, the type of sight you have is completely irrelevant to the bullet's trajectory.

Zero at 50 yards with common 5.56 ammo and the bullet will be back down to the line of sight at 200 +/- 20 yards.

This is simple stuff.........

Yes it is. 3 points on a horizontal plane, 1st point is at 0yds( your point of origin ) and 2nd point is at 50 yds, and the 3rd point is at 200yds. Your shot will originate at the 1st and rise through the 2nd and continue rising to a point approximately 125-150 yds away and then start to drop through the 3rd point. Remember, this is all minute of human. Personally, I like 25/300 and then pinging the steel at 500. If you can own the 3-500 yard range, consistently, your doing better than most of the population ever would. The problem then arises on your ability to acquire targets at that range and pop em before they disappear. Many experienced here will tell you it's one thing to shoot at a piece of steel or paper, it is a whole new book when shooting with your life on the line or better yet, someone Else's at the end of the barrel. That's practice you don't get in the real world, unless your TDY/HOT.

 

[atmay]

I am beginning to sight in an M-4 style carbine, flat top with the standard AR front sight and a removable rear sight (no carry handle).

The rear sight does not have room to adjust the elavation drum down to contact the base as does the stadard A2 sight. Will a 50 yard zero still accomplish the same 50/200 yard zero as the Santose method?

I'm guessing, from the info provided, that your rear sight is either not adjustable, or has a very limited range of adjustment?

Either way....if you're just using them as BUIS, set the rear sight as low as possible, then use the front sight to get the elevation correct for a 50yd zero, then let it be.

You might have issues with it if you start screwing with the elevation adjustments (if any) on the rear sight (ie..marked distances not being true), but if you leave it where it is, it'll be fine for the BSZ

 

[FPrice]

Thanks for the replies. I thought I would post some pics of my set-up since that might be somewhat clearer than my written description.

Here is my basic set-up, an M4-style flattop carbine with the standard front sight.

This is a close-up of the rear sight. It's a UTG brand recommended to me by John Lawor of Remsport. Notice that the aperture box is flush with the sight body and set at "6/3". As it sits now, it shoots to POA (as much as my 60 yo eyes will allow) at 50 yards. I may be able to access and loosen the screw in the top of the sight and set the sight wheel two clicks below the "6/3" as Santose recommends.

 

[atmay]

If that sight does have the set screw in the sight...that would be the best way to do it. As an FYI, all A2/Carry handle sights will require that adjustment for the 50/200....they almost always come from the factory set up to bottom out at 6/3

 

[LKB3rd]

Thanks, Mike. Now we're touching an answer. I have an AR15 with a 16 inch barrel. I'm not sure what you're asking when you ask me what the sights are. I can tell you I'm using iron sights on a detachable A3 handle with a 6/3 elevation marking on the rear sight knob.

Those are really cool sights, and if you look closely, there should be a TINY "z" on the dial. Just a click or two from the 6/3 or bottomed out. They are designed to be zero'd on that z at 25 meters. Then, you use 3 for 0-300 meters and the 4 5 6 are 4, 5 and 6 hundred meters. The 0-300 takes advantage of that arc to get you within a couple inches from point of aim at all of those distances.
That said, there are other ways you can zero them that are probably more useful for the type of shooting most of us do. ar15.com has some really good threads on zeroing those sites and the different ways to do it, I'll edit if I can find it with a link.