This - you can open up the index pin notch on the receiver a bit so the barrel can rotate, or file one side of the barrel index pin. The gap on the other side can be filled with a thin stainless steel shim which will be captured once you install the barrel nut. But, before you do that, you can determine whether the barrel is rotated in the receiver or the front sight tower is leaning by looking at the feed ramps. If the feed ramps line up perfectly, then it's the front sight tower that's leaning. You usually do have a little bit of rotation to play with for feed ramp alignment if you do want to make the adjustment.
Go Ukraine! Piss on the Russian dead.
Years ago, I was told by a big manufacturer that 13 clicks from center to zero windage was acceptable for a rear sight. I've seen rifles and carbines made by the same company require the rear sight to be adjusted all the way to the left to zero.
I've reindexed a considerable number of barrels to get the rear sight to no wind zero with the rear sight centered. It shouldn't have to be done on an expensive rifle or carbine made by a company that is popular on M4C, but it is more commonplace than I think acceptable.
Train 2 Win
I absolutely DO NOT want that gun. That is an unacceptable work around to me.... Especially going back to my example where it is not the FSB pinned off of TDC, but the receiver is not straight.
If someone here bought a gun, took it apart and saw that crap??? There'd be hell to pay for the manufacturer sneaking that crap into a customer's hands.
"What would a $2,000 Geissele Super Duty do that a $500 PSA door buster on Black Friday couldn't do?" - Stopsign32v
Does the front sight base appear to be canted to the left when the rear sight is held level? If you look at the muzzle, does the bore appear to be off center?
Train 2 Win
This is hard to tell. At least for me. And FSB forging "ears" are not always symmetrical where you could put a level on top.
This would be a unusual since the blanks are shaped after gun drill. (unless this is a Hammer Forge barrel of course) We did have a shillen barrel on a bolt gun that supposedly had this problem though.If you look at the muzzle, does the bore appear to be off center?
Could be just a bad barrel that throws bullets left/right.
I can't imagine getting an untrue FSB ream if they used a real reaming station. And if it's BCM or FN, they'd both surely be using this tooling.
It seems like this problem used to be more commonly reported in the past. I doubt they'll tell him what the problem is, but now I'm curious.
Last edited by markm; 01-27-22 at 15:22.
"What would a $2,000 Geissele Super Duty do that a $500 PSA door buster on Black Friday couldn't do?" - Stopsign32v
You mentioned above what the military deemed as 'acceptable' I believe. And you also mentioned selling one that you bought that was 10 clicks off? (that still falling inside of what you said the military would accept)
Plenty of other guys around here that would be able to diagnose the problem and possibly correct it on their own without selling or returning anything...
Point being - Depending on the problem and the severity - Sometimes that stuff can be adjusted / tweaked to the point where everything is perfect.
All of the parts we are discussing have 'tolerances' and there is no shame in having a shim here or there to make things closer to being perfect for a customer or an owner.
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