Proper sight picture for DD A1.5?? Pic please!!

[evidens83]

Stupid queston so bare with me. I finally took out my latest AR build to shoot. BCM mid length with FSB and DD A1.5 rear, Federal .223. Using a sandbag, I popped off 10 rounds at 25 yards. My grouping was all together BUT it was about 2-3" low from where I was aiming! I was using the smaller aperture BTW. With my last build I never had to zero my Troy BUIS, it shot where I aimed. With this build, its shooting low! Anybody care to post a pic of the proper sight picture when using the small aperture please??

BTW, my A2 FH is not completely alignedindexed(tightened with a wrench but its not aligned evenly if that makes any sense...) could that have caused a problem with my accuracy?

[voiceoftheright]

Did you try adjusting the front sight post? You know, zeroing the weapon? Just because your Troy didn't need adjustment doesn't mean the DD won't (or the front sight with the DD). What do you mean your A2 FH is not aligned? Do you mean indexed?

[Commander_Cody]

+1 VoiceoftheRight.

I just sighted in my new Spikes Tactical 1:7, 16". No optics. My DD fixed rear sight was a good 4" low.

3-4 clicks DOWN worked for me. Front sight post.

[Droppin Deuces]

O.o

[evidens83]

Did you try adjusting the front sight post? You know, zeroing the weapon? Just because your Troy didn't need adjustment doesn't mean the DD won't (or the front sight with the DD). What do you mean your A2 FH is not aligned? Do you mean indexed?

I figured I had to adjust the front sight post just needed re-assurance What do I need to adjust it? And yes I think the proper term is indexed. My A2 is not indexed would that cause any accuracy issues?

[scootergmc]

I figured I had to adjust the front sight post just needed re-assurance What do I need to adjust it?

Use a 5.56mm round.

[NiteQwill]

Remember FORS (front opposite, rear same) for adjusting sights for your grouping. Example, if you wish to move your grouping up and to the right: adjust front post down and rear right.

Proper sight picture is this:


Adjust as needed (each box is 1 cm):


Adjust front sight like this:

[evidens83]

Thanks NiteQwill thats the same sight picture I assumed but just making sure. When I depress the detent I just rotate the post with my fingers? I read somewhere I need to use pliers or a pencil eraser end??

And nobody still answered my 2nd question. Will my A2 FH not being properly indexed be an accuracy issue???

[Mute]

If by not properly indexed you mean that it's not perfectly vertical, at longer distances it can affect the accuracy. Also, if you have a rear iron sight with two apertures, for 25 yards, you should be using the one with the bigger aperture. FYI, if your rear sight is the same as the standard M16 A2 rear sight, there is a 2.5 MOA elevation difference between the two apertures.

[evidens83]

Why the bigger aperture? Wouldn't using the smaller of the two tighten my groups? And if the indexing does affect accuracy shouldn't I get it properly indexed before zeroing? Or else I would have to zero it again wouldn't I?

[Mute]

You can certainly use the smaller aperture, but understand that the two apertures will have differing zeros. The larger aperture zeroed for closer engagements and the smaller one for longer distances. If you prefer to use the smaller one just make sure you understand that it won't fire to the same point of aim as the larger one. And yes, you should get the front sight block properly indexed.

[Sumo99]

If you are doing a 25 yard zero, you can try this target.

http://www.bobdbob.com/~deneb/doc/targets/m16a2-25m-zero.pdf