Rifle Scopes AI + Steiner Zeroing Issue

[Luke M]

Hi all, my first but certainly not last time posting here after months of lurking.

I have a new Accuracy International AT308 topped with a Steiner M5Xi 5-25x56 (MSR reticule) in an AI one piece mount (0moa). The rifle was actually a birthday present! I've been shooting at long range for a few years now but mostly with diopter sighted target rifles, I'm looking to up my game a little and learn more.

I zeroed it at a hundred yards, but in order to get it zeroed I had to adjust it 3 mils right - which is half the right Windage adjustment range of my scope! Given the fact all the components I've used are of high quality and were correctly installed with a torque wrench, I'm having a hard time believing this is "okay". Can I just loosen the set screws on the Windage turret and zero it? I was under the impression if I did that that I'd loose half my windage adjustment range, which I'd really rather not do.

Are there any common causes of this in high end rifles? I'd hope that the likes of AI don't have bore alignment issues...

 

[Boon20]

Let me make sure i understand you
Are you wanting to know if its normal to use 3 mil right to zero?
Or about setting your windage back to zero from 3 mil right?

 

[brianf]

Are you sure your scope was mechanically centered to begin with?

have you actually measured (by turning Windage knob) that you are actually that far off center.

 

[Luke M]

Are you sure your scope was mechanically centered to begin with?

have you actually measured (by turning Windage knob) that you are actually that far off center.

I bought the scope new - it had been sat in its box for a few years and had never been fitted to a rifle, Steiner says they ship them optically centered from the factory. It turns the full 6 mil left and 6 mil right (stopping at either extreme), so I'm presuming it's properly centered.

 

[Luke M]

Let me make sure i understand you
Are you wanting to know if its normal to use 3 mil right to zero?
Or about setting your windage back to zero from 3 mil right?

I know how to set it back to zero from 3 mil right - loosen the two set screws, zero the turret, tighten them up - but is it normal to have to adjust that far on the Windage to get it zeroed? And if I zero it from 3 mil right, am I correct in thinking it will only turn to 3 mil right and I'll have lost half my available windage adjustment?

I shoot at 1000 on a fairly windy range, so it would be nice to have the full windage range available to me.

 

[Noob Sammich]

Since it sounds like the scope checks out, I would double check the mount and rings - make sure any gaps look even, hopefully you used a criss-cross pattern when you torqued down everything (like replacing a tire). Also, confirm torque for the mount and ring screws is where it should be, make sure your scope is plumb, and (be certain you pressed your scope mount forward on the rail before and while you torqued it down) - edit: disregard this last one, it's a one piece....

I'm not familiar with the AI one-piece, but everything should be lining up fairly well. Most I've had to adjust windage on a quality mount and scope has been 0.5 mil. 3 mrad sounds excessive to me, so I'd go over everything again.

That being said, you shoot at 1000 on a windy range, with a .308, with a 0 MOA scope mount?

 

[Luke M]

Since it sounds like the scope checks out, I would double check the mount and rings - make sure any gaps look even, hopefully you used a criss-cross pattern when you torqued down everything (like replacing a tire). Also, confirm torque for the mount and ring screws is where it should be, make sure your scope is plumb, and be certain you pressed your scope mount forward on the rail before and while you torqued it down.

I'm not familiar with the AI one-piece, but everything should be lining up fairly well. Most I've had to adjust windage on a quality mount and scope has been 0.5 mil. 3 mrad sounds excessive to me, so I'd go over everything again.

That being said, you shoot at 1000 on a windy range, with a .308, with a 0 MOA scope mount?

I've not taken this particular rifle out to a thousand yet thanks to covid restrictions, fingers crossed April is doable. The picatinny rail on the rifle is 20moa - I was under the impression that plus a 0moa mount is adequate? The mount is a used one which was given to me free with the rifle, if I have to buy another then so be it. I levelled the scope with a feeler gauge.

It was torqued down properly, proper torque driver, correct patten - though I will try remounting it this weekend. If the most you've had to adjust is half, 3 is a little disturbing and something has to be amiss.

 

[10ring'r]

Not being a smartass, BUT, I know AI, is a very expensive, accurate, professionally assembled, gun, but, could the action be off in the chassis?? If the scope was properly centered and all. Some fluke thing? Just "spitball'n" here.
Mac

 

[Luke M]

Not being a smartass, BUT, I know AI, is a very expensive, accurate, professionally assembled, gun, but, could the action be off in the chassis?? Some fluke thing? Just "spitball'n" here.
Mac

I wouldn't write it off, but that's what I'd investigate once scope and mount issues are entirely ruled out... Really hope that it's something easily fixed though.

I don't know what their customer service is like but I'm sure if there is a problem they'll go out of their way to fix it....or so I hope!

 

[10ring'r]

I wouldn't write it off, but that's what I'd investigate once scope and mount issues are entirely ruled out... Really hope that it's something easily fixed though.

I don't know what their customer service is like but I'm sure if there is a problem they'll go out of their way to fix it....or so I hope!

For the amount of $$, they want for one (I'm poor, so, not an option), I'm sure their c.s. is top notch.
I'm pretty sure it's something either, obvious and/or simple. Mac

 

[Boon20]

I know how to set it back to zero from 3 mil right - loosen the two set screws, zero the turret, tighten them up - but is it normal to have to adjust that far on the Windage to get it zeroed? And if I zero it from 3 mil right, am I correct in thinking it will only turn to 3 mil right and I'll have lost half my available windage adjustment?

I shoot at 1000 on a fairly windy range, so it would be nice to have the full windage range available to me.

Just making shure. Yes 3 mrad is alot i would try a different mount, rings or scope if you can, just to check.

 

[JMGlasgow]

The scope has more windage internally than the turrets will allow (6mrad each way). Zero the turret and I'd bet you still have 6mrad each way.

 

[Luke M]

The scope has more windage internally than the turrets will allow (6mrad each way). Zero the turret and I'd bet you still have 6mrad each way.

Just tried this, only had 4mrad right.

Where to go from here, should I get hold of another mount to try?

 

[JMGlasgow]

Do you really need 6 mrad of wind adjustment after you're zeroed?

 

[Luke M]

Do you really need 6 mrad of wind adjustment after you're zeroed?

It would be nice to have - I can hold off on the reticule easily enough, but it would be nice to have the full adjustment available to me on the turret.

 

[JMGlasgow]

You could try another mount or get adjustable rings.

I briefly had a M5 5-25 and I don't remember having any issues getting the full windage adjustment on a Rem700 with a EGW base and Steiner rings.