Lapping scope rings Why and How.

Rifle scopes, iron sights and optics. Spotting scopes and target acquisition devices.

Lapping scope rings Why and How.

Post by Homer » 12 Oct 2015, 6:05 pm

G'Day Fella's,

This is a subject that is, like so many technical tasks, misunderstood.

Here is an image of a good quality brand of scope rings (Leupold, in this instance, made for them by Warne), that have been correctly fitted to a scope base.
But despite being good quality and correctly fitted, there will always be manufacturing tolerance variations!
DSCN0771.JPG
DSCN0771.JPG (486.27 KiB) Viewed 8228 times

You can see where the black finish has been removed (by lapping), and the silver coloured ring material of these 30mm Steel rings, have been lapped to ensure a large alignment area and as stress free bedding surface for the rifle scope to lay in! Also, note the different areas of each ring that has material removed! The front ring, was quite out of alignment, but lapping them, sorted this out! Which is why we do this!!!
Now whilst I have removed some amount of material from the lower half of the rings, I haven't removed so much, so as to have 100% contact. There is a reason for this, so if you ever do this job, don't take off to much material!

Now, here's the scope in place. And in this instance, because of the amount of recoil generated by this rifle/cartridge, I also placed some 601 Loctite on the scope rings (Bottom and Top halves) prior to assembly, after I had worked out the correct position that the scope was to be in.
DSCN0775.JPG
DSCN0775.JPG (424.95 KiB) Viewed 8228 times


Hope that helps

Doh!
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Last edited by Homer on 13 Oct 2015, 9:56 am, edited 2 times in total.
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Re: Lapping scope rings Why and How.

Post by ebr love » 13 Oct 2015, 9:51 am

Homer wrote:This is a subject that is, like so many technical tasks, misunderstood.


I understand it, I just can't be stuffed :lol:

Good on you for the effort though :friends:
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Re: Lapping scope rings Why and How.

Post by Herdsman » 13 Oct 2015, 9:52 am

What've you got there, Homer?

Model 700 Long Range?
Shepherding bullets down range.

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Re: Lapping scope rings Why and How.

Post by south » 14 Oct 2015, 8:25 am

Homer wrote:Now, here's the scope in place. And in this instance, because of the amount of recoil generated by this rifle/cartridge, I also placed some 601 Loctite on the scope rings (Bottom and Top halves) prior to assembly, after I had worked out the correct position that the scope was to be in.


What's the amount of recoil where it warrants lapping the rings you reckon Homer?

What size and up?
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Re: Lapping scope rings Why and How.

Post by AusC » 14 Oct 2015, 10:04 am

Gotta protect the paint when you've paid that much for a Nightforce :lol:
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Re: Lapping scope rings Why and How.

Post by brett1868 » 14 Oct 2015, 11:22 am

I see the Why but not the How...curious if it's similar to the process I use.
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Re: Lapping scope rings Why and How.

Post by Apollo » 14 Oct 2015, 1:27 pm

Two things.

Was the Ken Farrell Rail bedded to the Remington 700 Action which itself can be quite out of allignment.

I would not consider Leupold Rings to be high quality, good yes but as the photo shows they are not perfect. Bet the lapping would be much different using Ken Farrell Rings as I have found.

If you pay very good money for high end scopes don't scrimp on rings and don't over tighten the ring mounts.

Brett, I think one "How" is on the BRT Web Site. At the time I was buying March Scopes the Lapping Kit came on loan to ensure it was mounted correctly. I might have the instructions as a PDF somewhere. I will say with my Ken Farrell Rail and Rings that the first stroke in lapping was dead true so I stopped going any further. It just showed everything was spot on and didn't need lapping.
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Re: Lapping scope rings Why and How.

Post by Supporter » 14 Oct 2015, 1:56 pm

brett1868 wrote:I see the Why but not the How...curious if it's similar to the process I use.


Rod and some lapping compound the same as every other way presumably :unknown:
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Re: Lapping scope rings Why and How.

Post by <<Genesis93>> » 14 Oct 2015, 4:38 pm

Its not worth not lapping the rings.... whether they are 'cheap' or spesssshal rings, a section of 1inch (precision) bar from the steel supply shouldnt cost more than 20 or 30 bucks...bit of compound, bit of hand work.....I would assume 30mm could also be sourced, 25.4 being a standard supply....

Its surprising how out of alignment the loopy ring halves can be (theyre the only one I've ever lapped).....
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Re: Lapping scope rings Why and How.

Post by pomemax » 15 Oct 2015, 7:55 am

http://www.opticsplanet.com/wheeler-sco ... g-kit.html
https://www.youtube.com/results?search_ ... cope+rings
spend $61 us . get the kit watch a video on youtube .
If you spend any sort of money on a half decent scope then have it spin in the rings or flip the rings off and damage the scope you will lap any scope from then on I even lapp my .22 scopes since then i have had only 1 lift a ring from the rail and yes i use loctite.
I am sure we have all read a post or 2 about the rail being out of alignment or some such ,using the kit tells you before you even get to the scope.
$60 odd and half an hour is it worth not too
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Re: Lapping scope rings Why and How.

Post by Redwood » 20 Oct 2015, 8:41 am

One thing I notice, no one ever does the top half of the rings?
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Re: Lapping scope rings Why and How.

Post by Gwion » 20 Oct 2015, 10:45 am

None ever shows the top half, but when you lap, the rings are in place so you are lapping the entire ring set at once.
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Re: Lapping scope rings Why and How.

Post by Homer » 20 Oct 2015, 7:34 pm

G'Day Fella's,

EBR Love, thats a Poor Attitude to have there son! LOL!!!

Herdsman, Rem 700 MLR!

South, Any and All scope rings, why wouldn't you!!
As for Loc-Tite, depending on the weight of the rifle, .30-06 cartridge and larger (powder capacity)!

Brett 1868, the correct way (look in the back ground of the images-Sinclair Lap), or show us how you do it!

Apollo, Yes!
These particular Leupold rings are very well made (by Warne) and I have no problems in the world both using and recommending them!
I don't consider that I have "Scrimped" by using these Leupold rings! I have been around long enough and set up enough rifles, to know quality when I see it and when I'm wasting mine and others money, which some appreciate!!! I also regularly use both steel and aluminum TPS rings and I consider them to be very good value for money!
Apollo, can you please explain "and don't over tighten the ring mounts." for us please?

Genesis 93, there is a bit more to it than that! You need to use a Lap made out of material that is physically harder than the rings, other wise the lap will soon be smaller than optimum and an odd shape.
Also, not all lapping compounds are the same! Some embed into both the Lap and the Rings. In the case of the latter, when finished and assembled, the compound then embeds into your scope!!!

Redwood, for what it's worth, I believe the top halves when tightened into place, are self aligning?

Gwion, I don't bother lapping the top half of the rings, other than to confirm there are no burs or dags on them!

Fella's FYI, occasionally on heavy recoiling, in particular target rifles, I will use 3 or if I thing it is required, even 4 scope rings to hold the scope in place!
Can anybody please explain Why I do this?
As you would expect, I lap these in 3 or 4 rings place and then go from there...........

Hope that helps

Doh!
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Last edited by Homer on 20 Oct 2015, 7:46 pm, edited 1 time in total.
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Re: Lapping scope rings Why and How.

Post by Homer » 20 Oct 2015, 7:42 pm

G'Day Fella's,
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Re: Lapping scope rings Why and How.

Post by Apollo » 21 Oct 2015, 12:12 am

Homer wrote:
Apollo, can you please explain "and don't over tighten the ring mounts." for us please?



I didn't think it needed explaining but anyway.

Some people think "Spuhr" are pretty high quality mounts, well all I know is they are very expensive. I purchased a March Scope that had been mounted in Spuhr Mounts and I think the guy must have been Superman as the mounts had left a very noticeable ring, in blotches around the scope tube. The looks of them certainly showed the mounting surface was not even and lacked proper lapping.

I have seen guys at a competition laying into their ring mount screws tightening them as much as they possibly could even as far as stripping a thread. One guy was quite surprised to see how much tension he had used after borrowing my torque wrench for his next change over scope. These aren't huge recoiling rifles. I'd bet they were using just as much torque as that on the base clamps to the rail.

Anyway, it was just a general reminder to all.
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Re: Lapping scope rings Why and How.

Post by brett1868 » 21 Oct 2015, 3:04 am

I turned down some stainless steel bar in the lathe (1" / 30mm & 34mm) and use it along with 280 grit compound to knock the rough spots off then finish with 400 grit. Similar process to the video except that I don't use alignment rods. I've found that certain manufacturer's rings need a lot of work whilst others need little or none so it's worth investing in quality bases and rings. I only recently looked into the lapping of rings after discussions with Apollo and have done a few of the rifles but not all. I have a 34mm 1 piece Era Tac adjustable inclination mount with a S&B PMII 12-50x56 which is a heavy bugger at 1.11kg on the DTA HTI. It's not lapped and despite many rounds of .375 Cheytac and 50BMG has never budged.

Proper torqueing of rings / bases is often overlooked but deserves attention as there's no point having lapped rings if the caps are not properly / evenly torqued down. Zero Gap Barrett rings which I use on a few of the bigger rifles have very specific torque settings as do the Era Tac mounts. A small torque wrench is very handy and can be purchased from a good bicycle shop.

I was shown many years ago to use cellophane tape on rings to act as a sort of non slip gasket and used that technique for many years and still do on some stuff. Sako rings now use a plastic inner ring type arrangement which seems to work, neither scope I have them fitted to has moved. Not much recoil from a 22-250 or .204 so I can't say for sure it'll handle the recoil of larger calibres.
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Re: Lapping scope rings Why and How.

Post by <<Genesis93>> » 21 Oct 2015, 9:04 am

The bar that I use is of tool or other harder steel alloy....even if the bar was of similar hardness, I wouldnt be too concerned about wearing the bar to a smaller diameter, given the rotational and longitudinal movement of the bar - ie. spreading any wear across a larger area.

I dont know about loctiting the tube.... or plastic liners for that matter, maybe a bit of rosin, once the rings are nicely lapped and concentric...
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Re: Lapping scope rings Why and How.

Post by ebr love » 21 Oct 2015, 9:47 am

Homer wrote:EBR Love, thats a Poor Attitude to have there son! LOL!!!


Hey, I said I wasn't knocking it :P
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Re: Lapping scope rings Why and How.

Post by Gwion » 21 Oct 2015, 8:38 pm

Homer, if you don't lap the top half of the rings, how do you ensure the lapping rod is running true in the bottom half?

Also, if you don't true the tops, it seems to me more likely that the top halves will mark the scope as any discrepancy there will be exacerbated.

Just honest questions.
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Re: Lapping scope rings Why and How.

Post by Redwood » 22 Oct 2015, 10:52 am

Gwion wrote:Homer, if you don't lap the top half of the rings, how do you ensure the lapping rod is running true in the bottom half?


My thoughts too :unknown:
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Re: Lapping scope rings Why and How.

Post by <<Genesis93>> » 22 Oct 2015, 11:39 am

I think there's a bit of confusion here.... who suggested not attaching the top of the rings??
They are attached, and tensioned so as to allow the bar to be rotated / slid...sufficiently to wear away the 'uneven-ness' and non-concentricity of the mounted rings....

There is a process, lap, tighten.... lap, tighten... at least the way I do it :unknown: :thumbsup:

The bar also allows the aligned installation of the bases
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Re: Lapping scope rings Why and How.

Post by Gwion » 22 Oct 2015, 4:30 pm

<<Genesis93>> wrote:I think there's a bit of confusion here.... who suggested not attaching the top of the rings??
They are attached, and tensioned so as to allow the bar to be rotated / slid...sufficiently to wear away the 'uneven-ness' and non-concentricity of the mounted rings....

There is a process, lap, tighten.... lap, tighten... at least the way I do it :unknown: :thumbsup:

The bar also allows the aligned installation of the bases


Absolutely. Same same. And as such, aren't you also lapping the top half???
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Re: Lapping scope rings Why and How.

Post by Homer » 24 Oct 2015, 6:24 am

G'Day Fella's,

Sorry but I'm left with the impression, you blokes still don't fully understand, what it is you are doing!
What we are trying to achieve here, is to create a stress free Bed, for the scope tube to rest in (the bottom halves of the scope rings). The scope ring tops, only task, is to clamp down and around the scope tube, to hold the scope in place in this bed!!!

Gwion, I'm using Gravity and the the Alignment value of the straight and parallel Lapping Bar (remember, that is what we are doing here), to ensure that what I'm doing (Lapping the bottom half of the scope rings), is true and correct!

Genesis93, where are the scope ring top halves going to go?
They are not Fixed!
Initially, they are Floating Parts that have no choice but to wrap around the contour of the scope tube (after all, thats what there job is and what they were designed to do), as they are being clamped together!
As I said before, as long as there are no burrs or daggs on them, all's good and there is no point in doing anything more to them!

Please, have a good think about what I have said before eg; "This is a subject that is, like so many technical tasks, misunderstood.", and again here, before you reply! Also, if as a result of the information I have brought to your attention, you now realise you may have been doing something that is incorrect, wasting your time or may have actually been detrimental to welfare of your property, that insecurity is your problem, please don't make it mine!!!

Doh!
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Re: Lapping scope rings Why and How.

Post by <<Genesis93>> » 24 Oct 2015, 6:48 am

No... homer, you're obviously in a whole other level of knowing....

Sometimes I'll have an argument with the mrs, and if we start going around in circles I'll just concede, and say "yes darling, you're right...." it's just easier that way
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Re: Lapping scope rings Why and How.

Post by Strikey » 24 Oct 2015, 6:51 am

I agree with you, Homer, my procedure for lapping rings is very similar to yours and there is no need to do anything with the top halves as they are going to self align when torqued down, I would bet most people probably don't tighten them down evenly so that would negate any lapping done to them. I once got carried away with lapping the top half of some Ruger rings, they were fairly rough and I needed to remove the burrs/machining marks, I now have a set of zero gap Ruger rings :lol:
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Re: Lapping scope rings Why and How.

Post by Homer » 24 Oct 2015, 12:45 pm

G'Day Fella's,

Genesis my "Dear", thank you for acknowledging that I've actually worked out what it is I'm doing and fully understand the Task, that I'm about undertake, before I start it!

Strikey, Ruger factory rings are The Pits!
If the scope slips in the rings, you can place appropriate sized shims of metal (Aluminium Coke Can), between the top of the scope and the underside of the top half of the ring (this will give you that Gap back)! But only do it to one ring at a time!
In other words, take the top off the Front ring, shim it and then tighten it back up. Then do the same with the Rear ring, that way you should maintain your scope zero (with a bit of luck)!

Hope that helps

Doh!
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Re: Lapping scope rings Why and How.

Post by Strikey » 24 Oct 2015, 4:04 pm

Homer, thanks for the compliments on the Ruger rings :sarcasm: I call them something worse than the " pits " but after I tightened them down 'til they stripped then backed them off a quarter turn ( that's the correct way of tightening stuff :lol: :lol: ) they are doing the job, its not a heavy recoil rifle, 6BR, so the Ruger " zero gap " rings will be staying. I will warn others that if you want to lap the top halves even though there is nothing to be gained, to be very watchful of what you are doing otherwise they might end up with a set of rings that won't hold anything ;)
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Re: Lapping scope rings Why and How.

Post by Homer » 25 Oct 2015, 7:03 am

G'Day Fella's,

Strikey, I forgot to Thank You for your compliment of trusting me and what I have stated!
Good luck with those Ruger rings mate!!!

Regards
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Re: Lapping scope rings Why and How.

Post by <<Genesis93>> » 25 Oct 2015, 9:07 am

Homer, I understand, you've come on to a new forum, want to make an impression of the guy in the know...but your reverse logic, just doesn't wash....

I suspect you yourself dont fully understand what and why you're doing it.... but by all means, keep on keepin on :thumbsup:

If the bottom halves are of a finish that requires lapping..... it would kind of follow that the top would also...

But by all means, you do it the way you 'understand'....

Strikey, the panel beater's /diy/out the back paddock with a piece of fence wire, a hammer and your lunch (which conveniently includes a can of drink) - solution to your problem of no gap.... is to shim it.

[don't get too wound up Homer, I'm just stirring you up mostly ;) ]

If you would like the considered response; the lapped internal of the ring would theoretically replicate the diameter and shape of the scope.... place a small amount of material, say under the top ring half, and you'll have a much reduced CONTACT AREA (defeating the lapping purpose) and force the tension screw to pull the ring so ever out of round...

Placing a longer shim to line a more significant proportion of the inside surface; will cause the inner diameter of the clamping area to be reduced, ever so slightly, while the clamped tube obviously remains the same.....will you be setting up random forces and stresses in the tube :unknown: hard to say and for a $100 scope I probably wouldnt be fussed..... but considering I'm a pedant, I'd fix the problem, not bandaid it.....I'd use the correct/engineering solution;

Take some material off the underside of the top ring half flat.

So, to sum up, my opinion, FWIW about lapping only half the rings is ... :lol:

:welcome:
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Re: Lapping scope rings Why and How.

Post by Chronos » 25 Oct 2015, 9:57 am

Apparently having 250 posts makes you an expert and wise elder of this forum :lol: :lol: :lol:

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