AR front-sight post adjustment question

[tteng]

My OLL is shooting too high, and my rear-sight bottomed out already. My front-sight post is the 4-notch type (every 90-deg). Do you know what's the approx. POI effect at 100-yrd for 1/4-turn of post? My OLL has a 20" barrel.

[ocabj]

1.25 MOA per 1/4 turn.

[tteng]

Thank you, sir

[jacques]

here's a good article.

http://www.odcmp.org/0607/default.asp?page=USAMU_SIGHTADJ_MOA

[high_revs]

Is the 1.25 that a standard only for 20"? I read the article and it doesn't account for different barrel lengths. I thought 1/4 front sight turn adjustments on a 16 vs. 18 vs. 20 vs 24 would vary because of the distance of the rear sight from the front sight. Or are the differences minute thus negligible?

I got this other info also from another post by law483

[Richie Caketown]

this thread also has some useful links

http://www.calguns.net/calgunforum/showthread.php?t=162723

[high_revs]

thanks Richie. Is it ballistics info why it they say 50/200? I didn't think about bullet flight path, though it makes sense if it is. I'll read that other thread more. Didnt' come across it though I usually start with page 10 on my searches and go backwards.

[Richie Caketown]

see thats where my confusion starts ... i think they are talking about the arc of the bullet as it flies . I dont know if the 25 yards is the same as 200yards or 50yds = 200yds. My Matech instructions say 25yds = 300yds .. so im kinda confused on which is true for a 16in barrel. I have read quite a few different opinions and just posted the link because it was more helpful than I

[RobT2K]

I like using this attached target for sighting in an A2.

I also like the revised IBZ for use at known distances like at the range

[high_revs]

thanks RobT2K. I actually downloaded that previous to posting in some older threads.