How much misalignment between scope rings is acceptable?

[E304life]

I’m installing some Talley lightweight scope mounts onto my new Winchester model 70 featherweight and I’m concerned with the amount of misalignment I’m seeing. When I place alignment bars in the rings and torque everything to spec, I’m seeing a vertical offset of about .008”. They have good alignment in all other directions. I don’t know if this height difference is due to the rings or if the receiver has a height difference between the front and rear mount locations. Do you think this amount of offset would put excessive stress on a scope or is it within expected tolerances? I’m considering shimming the rear mount up to bring them into alignment; is this an acceptable practice?

 

[Varminterror]

Use a solid alignment bar and bed those bases.

 

[rayatphonix]

Use a solid alignment bar and bed those bases.

I’ve had a Voere Titan 2 for many years. This particular rifle has a similar problem, but with a greater offset. I’ve yet to find a gunsmith willing to modify rings or bases. Varminterror, you just gave me an easy solution to a 10 year problem! Many thanks.

 

[entropy]

Shim the lower base.

 

[CoalCrackerAl]

Wow never thought of checking offset. Not about to either.

 

[rayatphonix]

Wow never thought of checking offset. Not about to either.

With the Voere I mentioned above, it’s visible as soon as you put the scope on the rings. I bought it from a LGS and got a very good deal, and I’ve often wondered if the previous owner sold it for that reason.

 

[CoalCrackerAl]

I have a Winchester 94AE the scope mounts are off. Found that out after i mounted the scope. Get it zeroed at 50 yards. And at a 100 the POI was high. I swapped the irons then for fiber optics.

 

[Varminterror]

Shim the lower base.

The photo appears to show the right hand base is tilted, not just lower. So there’s some work to be done if shim material is used, determining the thickness needed at one end, and the particular position - which may want to squish out if not securely affixed, which bedding the shim would offer. Or… of course, using a secure bedding material which negates the need for the shim, and eliminates that time suck of measuring and testing.

 

[N555]

At 8 thousands I just lap them. But bedding would also works fine.

 

[N555]

I have a Winchester 94AE the scope mounts are off. Found that out after i mounted the scope. Get it zeroed at 50 yards. And at a 100 the POI was high. I swapped the irons then for fiber optics.

A 2 inch height over bore a 50yd zero should also just about equal a 100yd zero. Yeah something was going on there.

 

[3Crows]

Consider removing and re-installing the rings. Maybe contact Talley as the two sets I have installed were dead on. Can you swap the bases front to rear? Can you install them with the bases held in alignment?

 

[E304life]

How much misalignment do you think a scope can tolerate without affecting internal function (elevation and windage adjustments, zoom etc...) I don't require or expect super perfect alignment, and i'm sure scopes are designed to tolerate a certain amount, i just dont have a feel for how much they can comfortably tolerate.

 

[jmorris]

How much misalignment do you think a scope can tolerate without affecting internal function (elevation and windage adjustments, zoom etc...) I don't require or expect super perfect alignment, and i'm sure scopes are designed to tolerate a certain amount, i just dont have a feel for how much they can comfortably tolerate.

I would say they could probably tolerate quite a bit or even align the rings themselves. I would imagine it’s 10,000:1 that owners of scoped rifles have even checked to quantify how much they are misaligned.

 

[Varminterror]

I would imagine it’s 10,000:1 that owners of scoped rifles…

…don’t take the time to learn how to shoot well enough for anything at all to matter.

…don’t ever challenge their skills or equipment to ever notice the compromised performance they induce by distorting their scope tube (or by not properly free floating their barrels).

…don’t pay close enough attention to their gear to notice the damage they’ve done.

…don’t actually know how to clean a rifle, or even know how to tell when it is actually clean.

…aren’t really shooters with any regular practice or use of their firearms.

**taking a little liberty here to illustrate the point that mass ignorance isn’t equivalent to technical validity. The fact most people can’t calculate tip on a meal without their phone doesn’t negate the fact mathematical functions exist in higher sciences which those folks have never even heard of, let alone comprehend, but remain to exist and are valid.

 

[redneck2]

I’ve seen scope tubes that have a visible dent. I now assume that’s from misalignment. I’ve never lapped rings, but it looks like a good idea

 

[earlthegoat2]

It’s hard to say whether it’s the receiver of the rifle or the scope base/ring.

This is the reason lapping and/or bedding exists. The threaded holes in the receiver have to be exact as do the holes in the base. So do the radii of the base contour to the receiver as well as the radii of the rings themselves to the scope tube. Stacking tolerances upon themselves like that is a recipe for being off a little bit every time unless certain prices are paid for extra high manufacturing specs in all of those areas just mentioned.

That seems like a daunting task but in reality it makes small difference most of the time and for hunting purposes, probably not much indeed. More precise disciplines could probably benefit from more exacting build quality.

In the meantime, lap or bed.

You may find out you need to bed the scope into the rings as well or lap them out.

I had an action once where I was able to see the scope base holes in the receiver were drilled off after I mounted a set of two piece Leupold ring/bases (just like the Talleys). I put the alignment bars on and found this.

It was off by a good bit. It seemed like too much, in fact. Sometimes you have to learn things the hard way so I proceeded to lap them in. Halfway through they looked like this.

Something is really off here it would seem. I was in it for a penny already so I plowed forward with the lapping. Got enough contact area and mounted the scope. I went to bore sight it and ran out of windage adjustment.

Crap

Lesson learned. I think I learned something else too. I had a set of single dovetail Leupold bases and rings. The type where you can dial in windage adjustment with the rear ring mount and it can pivot on the front dovetail so as not to torque the scope ring. Well that worked great and was just fine and the customer used the rifle for years (I told him all about it and didn’t charge him for the job) and was really happy with it. Still, the method I used and what I used it for did not make me feel too good.

I never knew what those dovetail scope mounts were for and I still don’t but that is one use.

 

[nettlle]

…don’t take the time to learn how to shoot well enough for anything at all to matter.

…don’t ever challenge their skills or equipment to ever notice the compromised performance they induce by distorting their scope tube (or by not properly free floating their barrels).

…don’t pay close enough attention to their gear to notice the damage they’ve done.

…don’t actually know how to clean a rifle, or even know how to tell when it is actually clean.

…aren’t really shooters with any regular practice or use of their firearms.

**taking a little liberty here to illustrate the point that mass ignorance isn’t equivalent to technical validity. The fact most people can’t calculate tip on a meal without their phone doesn’t negate the fact mathematical functions exist in higher sciences which those folks have never even heard of, let alone comprehend, but remain to exist and are valid.

...ignorance maybe.....overkill maybe.

 

[N555]

Didn't believe in lapping till my scope nazi buddy showed me how to set stuff up properly and it wasn't just on paper at 150yd, windage was off about 2 inches or maybe it was just me. I never zeroed a new rifle setup with 2 shots.

 

[entropy]

The photo appears to show the right hand base is tilted, not just lower. So there’s some work to be done if shim material is used, determining the thickness needed at one end, and the particular position - which may want to squish out if not securely affixed, which bedding the shim would offer. Or… of course, using a secure bedding material which negates the need for the shim, and eliminates that time suck of measuring and testing.

Good eye. I did not catch that first time through. That's what I get for looking at it first thing in the morning.

 

[jmorris]

I never zeroed a new rifle setup with 2 shots.

If you have a solid way to hold it during POA correction, it only takes one.

 

[Heir Kommt Die Sonne]

All this stuff makes me super paranoid about my own ability to mount a scope. I look at this stuff very carefully. I'll keep reading

 

[herrwalther]

I would lap those rings first. Pretty easy to do if you have the tools and know how. From there you can determine if you need new rings or bases.

 

[Varminterror]

I would lap those rings first.

Lapping these rings will only make them egg shaped. There’s an obvious miss in axial alignment, and lapping isn’t the solution. Lapping makes not-round into round. It shouldn’t be used when rings obviously aren’t aligned.

 

[Heir Kommt Die Sonne]

Lapping these rings will only make them egg shaped.

What does lapping mean ?

 

[tominboise]

You could always change rings to Burris Signature rings with the inserts. I think it would be a simple matter to get things lined up witht he inserts.