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4/7/2004 11:11:17 PM EDT
Hi all.  I've got a gov't profile barrel with an A2 FST.   I installed it on a Rock River flat-top upper using the JP float tube.

It came together pretty straight-forwardly except for some extra tapping/pounding on the FST pins to get them in/out (used small ball been hammer and Starrett punch).

I am using the LMT rear fixed sight on the flat-top.

There is not enough windage to sight-in at 25 yards.  It's still impacting about 4" to the right with the rear sight cranked all the left.

I've had a barrel with a slightly canted front sight tower before, but this one looks straight.   Looking from the rear and comparing the FST vertical-ity vs. the flat-top, it looks perfectly straight.

In the FAQ, besides the FST being canted, other causes for excessive windage are: bent barrel, barrel not seating under barrel nut square, and not square upper face.

How can I check for these and narrow down the problem?

thanks
-z
4/8/2004 5:27:52 AM EDT
[#1]
Have you bore sighted it?

Very easy, just clamp the barrel in a vise with a set of blocks, swing the vise so you can sight in on a distant verticle line (I use a power pole about a klick away), and ferify it is centered in the sights as well as the bore of the barrel.

This should point out any mis-alignments.

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