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6/18/2013 2:13:16 PM EDT
I have a new stripped barrel & bought a new undrilled FSB for it. I got the FSB & it turns out to be a F marked FSB. My question is, will this be a issue with the barrel being mated to a A1 upper receiver? For the record the barrel is a 14.5" Mid-length.

I have read so much, & with there being so many different opinions, I do not know what to believe. I would like to know if it will work in this combination sufficiently before having the barrel or the FSB drilled.

Any help is appreciated. Thanks!
6/18/2013 2:29:35 PM EDT
[#1]
If you are talking about that (I think .04" difference) in height you can just buy a different sight post. If that is not what you are talking about, then ignore me.
6/18/2013 6:15:17 PM EDT
[#2]
As shooter said if you are going to be using an upper with a carry handle and an "F" marked FSB you will just need to get a taller sight post than standard. I can pin the FSB for you if you'd like for $50 including shipping back to you. I ship back next day after receiving it. Sent you a PM.
6/18/2013 6:25:40 PM EDT
[#3]



Quoted:


As shooter said if you are going to be using an upper with a carry handle and an "F" marked FSB you will just need to get a taller sight post than standard. I can pin the FSB for you if you'd like for $50 including shipping back to you. I ship back next day after receiving it. Sent you a PM.


You almost got that right.  The F marked front sight base is .04" taller than an A1 front sight base so you will need to remove a corresponding amount from a standard sight post.

 
6/18/2013 6:30:49 PM EDT
[#4]
oops, flip flopped it. If he has not purchased a post yet I would just say get the correct size post before getting a standard one and removing material.
6/18/2013 6:46:06 PM EDT
[#5]
Yes, that is my concern with the F marked FSB & this A1 upper, is sighting it in. The FSB was stripped & I used parts I already had in hand to complete it.

BTW CraptinMypants I replied to your IM.

6/18/2013 6:46:13 PM EDT
[#6]
Yeah my bad I knew .04 ... I was just sure they had a conversion post for it, really thought I saw them on some site.
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