AR iron sight question

[NastyNate]

Hi, I am putting together an AR, and was wondering if there was a standard for sight plane height, or if manufacturers just guess. My situation is that I have a colt front sight tower, and my upper receiver is a YHM flat top. Will any bolt on rear sight work with the factory sight tower?

[synergy]

Hi, I am putting together an AR, and was wondering if there was a standard for sight plane height, or if manufacturers just guess. My situation is that I have a colt front sight tower, and my upper receiver is a YHM flat top. Will any bolt on rear sight work with the factory sight tower?

Is your Colt FSB "F Marked"?

It will work, you may just need to get a different front sight post if the FSB isn't "F Marked".
http://www.m4carbine.net/showthread.php?t=14753

[NastyNate]

nope, no F mark. just a C up top, and a bell with a Y in it on bottom.

[YBNORMAL]

if your fsb isnt marked with an "f", you will have to raise the sight post so high that the rounded base of it will be sticking up well past the shelf, as far as i know, this is OK, just looks a little strange, im also curiose about these issues because i want my BUIS to co-whitness on the bottom third of whatever optic i go with (prob m3 aimpoint with larue mount). i have a troy flipup rear on a flat top right now but im thinking of going with a 9 inch or so railed handguard and getting rid of the post sight for a troy flip up front, so many options.......

[synergy]

if your fsb isnt marked with an "f", you will have to raise the sight post so high that the rounded base of it will be sticking up well past the shelf, as far as i know, this is OK, just looks a little strange, im also curiose about these issues because i want my BUIS to co-whitness on the bottom third of whatever optic i go with (prob m3 aimpoint with larue mount). i have a troy flipup rear on a flat top right now but im thinking of going with a 9 inch or so railed handguard and getting rid of the post sight for a troy flip up front, so many options.......

All you have to do is buy a taller post.
http://www.bushmaster.com/products.asp?cat=21
PN: 9349056-M

[BerksCountyDave]

All you have to do is buy a taller post.
http://www.bushmaster.com/products.asp?cat=21
PN: 9349056-M

Back from basic?

[synergy]

Back from basic?

Yup.

Had health problems for like 6 weeks, and was gonna have to restart for missing too much training...and honestly, just found out that infantry wasn't something I wanted to do.

Once my heart wasn't in it, and I was going to have to go through red phase again with a new company/ platoon...I pulled the plug. Might go back for a different MOS later, but I'm home for now and enjoying it.

PM me your email address if you want the more detailed version.

[Suburban]

All you have to do is buy a taller post.
http://www.bushmaster.com/products.asp?cat=21
PN: 9349056-M

How about one with tritium?


BTW, it's not just a cosmetic issue, with the base of the front sight coming up too high. The front sight will wobble in the FSB if there aren't enough threads engaged.

[Legion_Prime]

How about one with tritium?

http://xssights.com/store/tactical.html

[synergy]

http://xssights.com/store/tactical.html

Careful with those...the tritium is only visable on 1 side, and the post doesn't rotate on the base like the Trijicon version does. So, obtaining a precise zero with them can be problematic. My buddy was like 2-3" off at 100yards with his, and had to pull it off his rifle to get dead on.