7.62x39 AR - zero distance?

[Deus Machina]

Alright, my google-fu is failing me and my understanding of ballistics charts is lacking.
.223 is easy and established, AKs are contested but I figure you can't go wrong setting the stock sight to 100m and zeroing at 100m, but my AR has MBUS, which don't have a range setting.
So I'm trying to figure out what range to zero at for general use.

I'm intending to use it for the range, maybe SD use, and on the off chance dad ever actually gets me out hunting deer or hogs, do so with that. Probably not outside of 150 yards.

 

[troy fairweather]

I'd like about dead on at 100 or a few inches high, that will get you to 150 and be about dead on close up.

 

[Dale Alan]

With MBUS I would zero at 50 yards and get real good with it , and then go out to 100 and see where it hits . If you are hitting good at 50 you will know if it's you or the gun/ammo at 100 .

 

[Riomouse911]

Due to the height of sights over AR barrels, if you’re sighting so the rising bullet strikes bullseye at 50 it only hits about 1/2” above line of sight until it’s on the bull again as it drops at about 115 yards +/- a few.

A 25 yard zero puts a bit of a rainbow arc on the bullet. It rises almost 4” above the sights at 100 yds. and drops down to strike bull again just short of 200.

This has been my experience with my 7.62 AR with a 16” barrel and generic 123 gr fmj ammo.

Stay safe.

 

[someguy2800]

I zero mine at 100 yards and its like 5" low at 200 which works out perfect for the ballistic reticle on my scope. For iron sights I would probably sight it at 150. That will be like 1" high at 100 and 3" low at 200.

 

[benEzra]

It somewhat depends on your sight height, but you might try 50 and see how close it is at 200. Years ago I had a SAR-1 with a Kobra (a rifle I am still kicking myself for letting go), and as I recall, a 50-yard zero made it a couple inches high at 100 and pretty much right on at 200, within the limits of the ammo I was shooting, which was 123gr or 124gr steel case. Not sure how a Kobra’s height over bore compares to an AR optic, though.

 

[d2wing]

100 yards for me. I am not likely to shoot it beyond that.

 

[Archie]

First: Decide on the presumed target and the size of the desired impact area.
Second: Divide the desired impact area in half.
Third: Determine the velocity of the round and bullet (impact) drop at various ranges out to what you presume is the outside limit.
Four: Find where the impact of your fired shot is that 'half-distance' (from the second step) above line of sight.
Five: Find where the impact of your fired shot is that 'half-distance' (from the second step) below line of sight.
The sight in zero range will be at either of two places the trajectory of the bullet crosses the line of sight. Probably easiest to read the tables about 'how high' that would strike at 100 yards.

A deer, for instance has a heart/lung area (usually considered the desired area) of about eight inches. So one wants to cover the area both four inches below and four inches above the 'perfect shot'. So using your chronographed information (best) or the factory advertised velocity (second best), check on a drop table to find where the velocity of the load in question hits a maximum of four inches above the line of sight and then hits four inches low. Then check the strike of the bullet at 100 yards. Sight in at 100 yards at the height predicted. Sight picture is the center of the perceived 'target zone'.

Military 'battle sight zero' is similar but a bit easier. The presumed torso 'target' of an enemy soldier is 18 inches. The sight picture is the level of the belt line. The sight setting is such the highest point in the trajectory is 18 inches above line of sight. At some further distance, the strike of the bullet will 'drop' to be at belt level again; where upon the shooter aims at the shoulder level.
Which is why a 1903 Springfield rifle with issued 150 grain ammunition had a battle sight zero capability of over 500 yards.

Yes, it's possible and even common to sight in at two inches high at 100 yards and call it good. Recognize one's limitations. (My old eyes can't hold metallic sights on much anything at 500 yards anymore.)
You're on your own for windage.

 

[Mosin Bubba]

I sighted my scoped CZ 527 in for 100, but that's just for plinking. It might work for hunting though... there's not going to be a lot of bullet rise from the muzzle to a 100 yard zero, and not a lot of drop from 100 to 150. I haven't put my 527 on paper in a while, but I would be surprised if the bullet trajectory was greater than +/- 3" in that whole 0-150 band.

Also, if shots over 100 yards are in order, I'd say that a scope is too.

 

[DMW1116]

I’ve taken to sighting my rifles in for a maximum point blank range for a 6” diameter target. Mine fall into two groups. 30-30 and similar cartridges are 3” high at 100 yards. That keeps me in the circle out to about 175 yards. That’s with a sight height of 0.75”.

For 223 and 308 and most other calibers I’ve looked into, I sight in at 3” high at 150 yards. For 55 grain 223 that will keep me in the 6” circle out to about 300 yards (in theory, as my local range goes to 200). For 308 type rifles it’s good to 250ish. For magnum calibers and stuff like a 270 Winchester the 3” high mark might be out to 175 yards, but I’ve not investigated. It really depends on what you are doing. If you want to shoot quarter size targets, you basically have to zero at the desired distance. I want to stay in an 8” circle so I knock 2 inches off for a margin of error and use a 6” target.

 

[M1key]

Colt 20 inch with irons:

50 yard zero, close at 200 with factory 123 loads or handloads. I might use 123 Gold Dot, Hornady SXT, or Sierra 125 Game kings for a reasonably effective game load.

M

 

[briansmithwins]

There is no great zero range for 7.62x39 like there is for 556.

What I do for general shooting is zero at 200 yards. You should be less than a inch high at 50 yards, 2-3 inches high at 100, and ~14 inches or thereabouts low at 300.

BSW

 

[DMW1116]

I’d say after a little digging decide the diameter of the smallest target you want to hit and set it to hit that high at 125 yards.

 

[Deus Machina]

Well, I don't have access to a range longer than 100 yards, that I know of.
So general consensus here seems to be about 50 yards. Long as I could hit a Coke can between 10 and 100 without having to adjust much, that's good enough for me.

 

[briansmithwins]

Well, I don't have access to a range longer than 100 yards, that I know of.
So general consensus here seems to be about 50 yards. Long as I could hit a Coke can between 10 and 100 without having to adjust much, that's good enough for me.

If you're just using AK iron sights and don't normally shoot more than 100 yards out then I'd just leave the rear sight set to the 100m setting. It's close enough until you get out to more than 300 yards out or so.

BSW

 

[Deus Machina]

If you're just using AK iron sights and don't normally shoot more than 100 yards out then I'd just leave the rear sight set to the 100m setting. It's close enough until you get out to more than 300 yards out or so.

BSW

AR.
I have an AK, and that's what I do with it. 100 for 100. Well, 109.4 for 100, but close.
But my AR isn't factory-set or adjustable, which is why I asked.