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5/11/2010 7:24:37 AM EDT
I know the correct way to do this is to use a standard, non F FSB.



I have an A2 upper already, and am looking for a 14.7" barrel (perm attached A2) with a standard FSB, but I can't find one. CMMG offers the 14.7" like I want but only with an F marked FSB.



Is it possible to make the F marked FSB work with an A2 upper?
5/11/2010 8:07:46 AM EDT
[#1]
take .040 off the front sight post if need be?
5/11/2010 8:10:09 AM EDT
[#2]
Could it really be that simple? I had thought about that, since they sell extended posts for standard FSB when used with a flat top upper. Could I just screw the post farther in, or file it down?
5/11/2010 8:22:50 AM EDT
[#3]
Yes, it's that simple...or buy a 0.040" taller FSP when going in the other direction.
5/11/2010 8:30:43 AM EDT
[#4]
It is.  You will have more room in the FSB to screw the post in making up for the .040 taller FSB - raising the POI.  It's the other way that sometimes requires the taller sight post.  (non "F" with flattop on a carbine).  As said if you can't get it to work (which you should be able to without any problem) file the post or play with the elevation on the rear sight drum of the A2.

A general statement is that:  Non "F"  FSB's on a carbine and flat top are sometimes a problem and require a taller front sight post or a "lower" carry handle.  All other combination's will usually work.
5/11/2010 8:32:44 AM EDT
[#5]
Perfect, that tells me exactly what I needed to know.



Thanks, guys!
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