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3/31/2009 8:49:28 AM EDT
Im putting a new FSB on a barrel and will be using set screws to hold it.
what is the best way to get the sight base centered with the top dead center of your barrel?
I can eyeball it but i dont think that will be good enough.
Help??
3/31/2009 8:54:28 AM EDT
[#1]
Randall from ar15barrels.com uses a rod


3/31/2009 9:08:13 AM EDT
[#2]
Can someone send me a side view of this bar??
3/31/2009 9:25:54 AM EDT
[#3]
Or any other ideas????
Please!
3/31/2009 9:29:57 AM EDT
[#4]
Quoted:
Or any other ideas????
Please!


Flip the whole upper receiver up-side-down, and place onto a flat surface such as a counter top. This technique has gotten me to within 2-3 clicks of windage when installing folding FSB's. One factor that can affect the alignment would be if the FSB ears are slightly different heights.
3/31/2009 9:30:18 AM EDT
[#5]
Is this for a gas block or a Front Sight Base?
If you're using set screws with a conventional FSB, it's probably not going to stay still anyway.

I would never settle for anything less than straight pins on an FSB... but much prefer Taper pins.
3/31/2009 9:46:43 AM EDT
[#6]
Its for a front sight base.  Im going to slide the base on get it straight snug down the set screw apply some green locktite let it site over night then take out the set screw run a drill bit down the set screw hold and dimple the then put the set screw back in and torque it down. but i need to make sure the fsb is straight before I put on the locktite and dimple the barrel for the set screw.
3/31/2009 10:35:24 AM EDT
[#7]
Quoted:
Its for a front sight base.  Im going to slide the base on get it straight snug down the set screw apply some green locktite let it site over night then take out the set screw run a drill bit down the set screw hold and dimple the then put the set screw back in and torque it down. but i need to make sure the fsb is straight before I put on the locktite and dimple the barrel for the set screw.


Who says that TDC for the FSB is going to make it zero in the center of the windage anyways?  They are castings, not precision machined components.

Why not use your setscrew to hold it, adjust your rear to center windage, shoot it at the range at 100 yards or more, then use your tap hammer to bump your front sight over for windage, then do the green locktite and dimple gig?

You just have to be really careful getting it in and out of the case.  One setscrew isn't much holding power when you have a 2.5 inch lever putting force into it.

Brett
3/31/2009 11:05:12 AM EDT
[#8]
http://www.quarterbore.net/forums/archive/index.php?t-183.html
3/31/2009 11:36:14 AM EDT
[#9]
Hows about a jig?

3/31/2009 11:43:31 AM EDT
[#10]
One trick I've heard is to run a piece of string through the rear peep down the length of the barrel and use it as a guide.  Never had to try it though, as my FSB is taper pinned.  Set screws don't sound like they'd be all that stable to me, but YMMV.
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