What Front Sight Do I Have?

Discussion in 'AR15' started by ZombieHuntAR15, Sep 17, 2010.

  1. i just noticed on my front sight i don't have a <F> or <B>, I don't ever plan on putting a rear sight on this one only scopes, but it'd be nice to know for when i get a low-pro gas block and maybe build a 3rd AR i could use this front sight on the barrel.


    heres the other side

  2. jmp8927

    jmp8927 G&G Evangelist

    Just looks like a standard AR-15 front sight assembly. All of them like it are pretty much identical.

  3. yep, have to agree with JMP. Looks like your standard AR front sight.

    I see your concern is, or you're concerned about it not having the "F" or "B" that many say they have, I wouldn't worry about it.

    Truth is, I never and still don't really know what that was all about though? lol But, if I had to guess, I'd say it has something to do with the mold used or the manufacturer or something like that?

    Trust me, if I'm wrong, SOMEONE WON'T HESITATE TO POINT THAT OUT. But then, you're also sure to get a correct response. lol So, you're welcome. lmao
    Last edited: Oct 4, 2010
  4. Darkfront

    Darkfront G&G Evangelist

    The difference between the 'F' marked Front Sight Base and a non-'F' marked is the height. It's almost negligible, but it's enough to mess with elevation adjustments when used in conjunction with a rear sight.

    F marked FSBs are designed for A3/Flat top receivers. (1.98")
    Non-F marked are designed for A1/A2 receivers with an integral carry handle. (1.94")

    If you intend to put your non-F marked FSB on a flat top receiver, you will need to replace the sight post with a taller one from my understanding.
  5. jmp8927

    jmp8927 G&G Evangelist

    ^I just learned something. Sweet!
  6. ranchman

    ranchman G&G Newbie

    Front sight

    My S&W carbine with a removable carry handle has a F marked front sight.
  7. Darkfront

    Darkfront G&G Evangelist

    That's appropriate because it's a flat top. The rail + carry handle accounts for the extra .04" It has to be an non-removable carry handle for the FSB to non-F marked.
  8. Sprout47

    Sprout47 G&G Enthusiast

    Darkfront hit it - the F marked sights are taller than a standard A2 front sight. How it matters is if you put a mil-spec BUIS on a flat top upper with an A2 front sight the elevation won't zero properly - which could be a big issue especially if intent is on using iron sights or a co-witness with optics. It will just be off. A minor thing but we are men of perfection! :D
  9. M14man

    M14man I don't take prisoners... Forum Contributor

    My calculations may not mean a whole lot, or be correct...but I calculate the sight height difference causes about a 6 minute of angle impact difference.
  10. What other have said. The F is for Flat top uppers. All your folding rear sights are made to used with front sight assemblies that are F marked. There is a difference in height with F and non F marked. When the detachable carry handle was created it caused the rear sight's height to be changed and front had to be changed accordingly.