Need help with AR 15 Mechanical sights

[Rule3]

I took a scope off one of my AR's and put a carry handle on which has A2 rear sight.

The sight has markings of 0, 5,10,15 rather than fractions like 8/3? I am guessing it's meters??

All the research I have done does not show these whole numbers?

Regardless I want to set mechanical zero. I moved the front sight so the base is flush. I turned the rear sight down tight (which actually indicates UP) so it's on 0 (zero)

My main question is if all elevation is supposed to be made with the front sight what does the elevation feature of the rear for??

I have the Amy 25 meter zero test targets but were should I have this rear sight elevation set at??


Why cant elevation be changed with the rear, rather than messing with the front?

Only shoot 100 yards max.


So is this now at mechanical zero? If so what distance is that supposed to be? I have watched some videos but can't find this explained.

Thanks

 

[jmorris]

It is not a fraction, the 3 is 300 meters, as you turn the knob you pass by 400, 500 etc until your at 800 meters after a full revoultion. Unless you have the 6/3 cam like a carry handle sight then your 300 and 600 respectively.


This should help you out.

http://www.armystudyguide.com/content/army_board_study_guide_topics/m16a2/zero-and-m16a2-rifle.shtml

 

[Rule3]

Thanks. I have that study guide, I still do not understand why mine is in whole numbers, 0,5,10 etc.

From that article:

(2) Rotate the elevation knob down until the range scale 8/3 (300-meter) mark is aligned with the mark on the left side of the receiver (Figure 107).

As I do not have those marks do I set it at 3 rather than 0?

 

[W.E.G.]

The 5-digit intervals are nominal reference points only.

Typically found on sights that are threaded to the finer-pitch "match" increments.

Most likely, on the OP's rifle each click is worth a half-minute, or a quarter-minute.

Measure it and find out.
Movement of 0.006" equals one minute of angle movement of the sight on most AR's.

 

[W.E.G.]

The 3/8 sights are a much coarser thread pitch.

OK (but obsolete) for military applications.
Lousy for target shooting.

 

[Rule3]

It lloks like this. Not sure who makes it, I have had it for years. Notice the wheel marking. The reviews call it a 6/3 but it's not marked that way unless that is just a standard name?

So if my 3 is equal to 300 meters or 8/3 then per the Army manual I should move it one click up?

http://www.midwayusa.com/product/61...andle-with-a2-rear-sight-ar-15-aluminum-matte

So can I be adjusting elevation with this rear wheel rather than using a sight tool on the front?

 

[Highcaliber]

The front sight post should be used to establish your baseline "mechanical zero" not your BZO.

 

[forestswin]

it seems you have national match indexes
you need to see these destructions

Armalite, Inc Technical Note 26
Zeroing Armalite National Match Sights

Issued February 4, 2003
Revision 1



http://www.armalite.com/images/Tech...ing ArmaLite National Match Sights, 9901….pdf

for other "NEAT" technical notes
see this page

http://www.armalite.com/Categories.aspx?Category=35e8a0b0-7e71-4af3-b335-53f4a7dc8f08

 

[Rule3]

Thanks Forest. I believe you have found the answer!

Now I am thinking these sights may be for a a AR 10 , 308 Cal?