Okay, I took my Pony builds out today and test fired them and sighted them in. Both are C7 type rifles with A1 rear sights and normal, G.I. front sight bands.  The rifle shot at dead center at 25 yards with no adjustment whatsoever by sheer luck.  The windage for the rear site is just a bit off to the right basically the way I assembled it.

 The carbine however shot WAY to the left at 25 yards and once zeroed, the rear sight is now WAYYYY to the right.  Not all the way over but very noticeably off center.  So much so as to be annoying, unlike the rifle which is perfectly fine where it is.

 Since the carbine is now zeroed, I want to move my BULLET IMPACT about 3 or 4 inches to the right so that I can adjust my REAR SIGHT back to the left a few turns or so in order to have nearly equal windage on the left and right.

 Here is the question:  If I file the left side of the barrel locator pin notch to move the FRONT sight to the left so that I can move impact to the right, do I need to shim or peen the right side of the notch?  When tightening the barrel nut the force of the nut tightening up will tend to torque the barrel to the left ( if you are looking DOWN the barrel from the proper end of the gun ) anyhow.  Will the friction of the barrel nut keep everyting in place or should I peen the right side also?

 If I must peen the right side, what is the BEST and most professional way to do so?


Thanks, guys!

i have had canted front sights and before possibly ruining the upper i would hit the fsb with a rubber mallet in the direction you need it to go and see if that doesnt work. everytime i have done so it worked out great.

Quoted: i have had canted front sights and before possibly ruining the upper i would hit the fsb with a rubber mallet in the direction you need it to go and see if that doesnt work. everytime i have done so it worked out great.

I have heard this works, also.  Did your rifles maintain zero after re-adjustment?

  As a matter of note, when I was building the carbine I did have to back the nut off a bit in order to line up the gas tube gauge, I may have caused the improper cant, myself.

 Maybe I'll give that a try.  How hard should I give this baby a smack?  How should I secure the upper receiver?  In my normal action blocks?

 Keep the advice coming guys.  I may need a back up plan....and I would like a good consensue on what to do before I go smacking or cutting.

 Hurting the upper isn't too big of a deal to me, I'll just buy another if I screw it up...but still......I'd like to try to fix this one as everything else is perfect function....so why screw with a good thing?

Thanks again, everyone!!!!

i smacked it pretty hard but with a rubber mallet held zero and was damn near dead on.


with your bbl. nut i wouldnt have just backed off to align the gas tube, i would have started over loosening all the way and retightning it till the gas tube lined up or tightened a bit more to line it up.

tag for night crew advice

Quoted: i have had canted front sights and before possibly ruining the upper i would hit the fsb with a rubber mallet in the direction you need it to go and see if that doesnt work. everytime i have done so it worked out great.

Here's some night crew advise for ya...

During the day or night, filing and shimming it is NOT the prefered method to correct your problem...
You could either go through all the BS of loosening the barrel nut and then try to get the barrel to rotate and then re-torque the nut, OR, you can take eklikwhoa's advice and easily fix it by using a mallet to whack the FSB to rotate the barrel in the direction needed to center the rear aperture for zero POI... You can do this easily at the range and it only takes a few seconds to do...

Quoted: Quoted: i have had canted front sights and before possibly ruining the upper i would hit the fsb with a rubber mallet in the direction you need it to go and see if that doesnt work. everytime i have done so it worked out great. Here's some night crew advise for ya... During the day or night, filing and shimming it is NOT the prefered method to correct your problem... You could either go through all the BS of loosening the barrel nut and then try to get the barrel to rotate and then re-torque the nut, OR, you can take eklikwhoa's advice and easily fix it by using a mallet to whack the FSB to rotate the barrel in the direction needed to center the rear aperture for zero POI... You can do this easily at the range and it only takes a few seconds to do...

Sweet...may give it a shot this morning!!!!  Thanks!

Okay, I went to my buddy's shop and yanked the barrel, cleaned everything and redid the whole mess. This time I timed everyting off of the torque ON direction ONLY.  Barrel has indexed to the left nicely but not too much!!!  This should move my groups to the right enough for me to get some left windage action going on my rear drum and even things up a bit.

Thanks for all of the tips, Guys!!!!!  I'll report after my shoot tomorrow!!!

Quoted: i have had canted front sights and before possibly ruining the upper i would hit the fsb with a rubber mallet in the direction you need it to go and see if that doesnt work. everytime i have done so it worked out great.

I have seen several folks mention this. I have a couple of newbie questions.
 1- How do you support the FSB when you "whack" it? Is the upper in a vice or are you laying it flat on a forgiving surface?

 2- What direction do it want to push it if the rear BUIS is far right of center?