Question about zeroing

[Entryteam]

Hey folks,

I am experiencing a thing I've never dealt with before. Today, I took a new rifle out to the range to zero it at 25y and I have got the elevation spot on. But the rear sight's aperture is all the way to the right side and is still hitting an inch or so left. I cannot adjust any further. My only idea is to go back and start over and just simply try again.

Any of you got any advice you can give? The sights are ARMS 40L, which ive used on many other carbines for many years and never have I had an issue with.

I'm kinda stumped.

[DaBigBR]

Factory gun or build? Type of handguard? Is it grouping consistently (sounds like it is but confirming)?

[Entryteam]

Factory gun or build? Type of handguard? Is it grouping consistently (sounds like it is but confirming)?

Factory. Ruger AR556. handguard is moot, the rear sight sits on the top of the upper receiver. And it's grouping very consistently, which is the maddening part.

[HKGuns]

Factory. Ruger AR556. handguard is moot, the rear sight sits on the top of the upper receiver. And it's grouping very consistently, which is the maddening part.

Not moot if the front sight or rail is canted.

[georgeib]

Not moot if the front sight or rail is canted.

This.

90% certain your handguard isn't centered, or the front sight isn't installed correctly. The other 10% is that the barrel wasn't installed correctly.

[Entryteam]

This.

90% certain your handguard isn't centered, or the front sight isn't installed correctly. The other 10% is that the barrel wasn't installed correctly.

well crap

[TexHill]

Call Ruger and tell them about your issue. They will issue an RGA and fix it.

[grizzman]

If you've used the same rear sight many times before, then it should be pretty easy for you to remove one from another rifle that's properly zeroed and install it onto the Ruger.

If the sight that allowed a proper zero on the other rifle doesn't do the same on the Ruger, then the rifle is faulty and needs to go back to Ruger.

[jsbhike]

Out of curiosity, could you bore sight it?

A few years back I had a barrel(fixed fsb) and an upper from 2 different reputable companies that could be bore sighted for windage with rear roughly centered, but gave near identical results to what you are getting when shooting although groups weren't great.

Ended up being the barrel which the manufacturer replaced. No obviously dinged up crown or anything like that, but the replacement zeroed with sight roughly centered and much better group size.

[georgeib]

well crap

If it was me, I'd try to figure it out and see if it's something I can repair. You didn't mention if the rifle has an FSB or a free float rail. If it's a free float, I would remove the handguard and the barrel, and then reinstall them to make sure it is done correctly, and that the handguard is properly centered. If it's an FSB, it's probably canted and will need to go back to Ruger.