AR front sight BURIED to zero it...

[mikepro8]

So, a few months ago I bought a Colt LE upper (6920 or 6950, I think) I mounted it onto an Anvil Arms Lower and put a standard carry handle sight on it.

I went to sight it in over the weekend and had to BURY the front sight to get it zeroed at 50 yds. Any ideas?

I checked the rear sight - nothing odd that I can see.

[jpavoncello]

If you have an "F" marked front sight, that is probably your problem. The "F" front sights are for use with flat topped uppers, not carry handles.

[mikepro8]

Just checked the front sight post -
the only markings on it are "G4 I1"

[TonyF]

So, a few months ago I bought a Colt LE upper (6920 or 6950, I think) I mounted it onto an Anvil Arms Lower and put a standard carry handle sight on it.

I went to sight it in over the weekend and had to BURY the front sight to get it zeroed at 50 yds. Any ideas?

I checked the rear sight - nothing odd that I can see.

If the carry handle is aftermarket that might make a difference.

The rear sight may also be out of calibration. Get hold of a current (M4) technical manual and make sure the rear sight is set up properly.

[TonyF]

If you have an "F" marked front sight, that is probably your problem. The "F" front sights are for use with flat topped uppers, not carry handles.

The 6920 is a flat top.

Not using an "F" marked FSB on a 16 barrel with an M4 profile usually results in the opposite problem (e.g. the front sight post has to be cranked "up" to the point that there are barely any threads holding it in place).

My best guess is the rear sight is out of calibration.

[JDePietro]

Two thoughts come to mind.

Although I have had little sidearm training I have had much more rifle training and most of it in the military style.

Your rifle was designed to shoot in the ranges of 400 to 600 meters assuming it is a carbine you can adjust that range to 300 to 500 meters respectively. Now stick with me because my instruction was with the M14 or M1A and I am just recently getting into the AR scene.

First and foremost you must understand that there is a difference between meters and yards.

1 meter = 39.37 inches or 3.280 feet. Confused?

Lets use 300 meters as a guide. 300m = 328.038 yards or rounding down 328 yards.

28 yards rounded up, is 30 yards and 30 yards is roughly 1/10th of the total distance, big difference when shooting for precision.

With this understood lets talk about your sights.

Set at 100 meters or 109 yards your rifle is going to shoot high at 50 yards. To compensate for this most instructors use the 6 o'clock method.
Aiming your rifle at 6'oclock or at the bottom of the target will bypass your rifles preset distance marks and your shots will strike the center if you do your part.

http://images.google.com/imgres?imgu...3Doff%26sa%3DN

This site should help you understand the principal.

Good luck and happy shooting.

[mikepro8]

Thanks for the input so far, guys.

The carry handle isnt aftermarket, its actually a Bushmaster (from another AR I have).

Secondly, I am shooting 6 o'clock hold - its just my preference. At 50 yards, I was about 24 inches below the bull when I started shooting!

Doing some searches out there on the internets... see what other interesting info. I can find.

[Kaos]

I had similar issues sighting at 50 with an A1 upper and 16" barrel, solution was to sight in @ 100 yards using a 6 oclock hold, shoot @ 200 using a center hold and for 50 was a slightly higher than center (frame hold)

Im not too dead set on it being dead nuts accurate at the moment because I intend on using a 20" upper at some point for that.

Best I shot using the above sight method is a 402 at the last club CMP I shot (jcg style shoot)

[TonyF]

The carry handle isnt aftermarket, its actually a Bushmaster (from another AR I have).

I meant if it isn't a Colt Carry Handle. Did you buy it new or used? If it was used I'd be particularly suspicious that someone may have been tampered with it.

Secondly, I am shooting 6 o'clock hold - its just my preference. At 50 yards, I was about 24 inches below the bull when I started shooting!

That shouldn't matter. It shouldn't be off that much.

Doing some searches out there on the internets... see what other interesting info. I can find.

I think you can DL the tech manual at arfcom.

[mikepro8]

posted my same problem on m4carbine.net.
Got an interesting response....
A few people say that the Bushy carry handles are NOT mil spec, that they are actually a bit shorter than mil spec.
The Colt front sight aligned with a non mil spec carry handle may be the problem.
Go Figure!!