Is Scope Lapping necessary?

[Grumulkin]

Anyone never lap and never have a problem?

I bought a ring lapping kit and sold it a few years after not ever using it even though I've mounted bunches of scopes. Most of my scopes are Leupold Mark 4 and Nightforce. Most of the current rings are by Warne, Blaser and SSK Industries. I have had scopes move from recoil with certain rings but I'm not sure lapping would have solved the problem. I solved the problem by buying better rings.

 

[Walkalong]

A picture is worth a thousand words. Do you know when that article was written?

I do not. Been around a while though.

 

[Walkalong]

I solved the problem by buying better rings.

Yep.

 

[Aim1]

Yep.

So basically it comes down to quality rings don’t require lapping?

 

[Infidel]

So basically it comes down to quality rings don’t require lapping?

Yep. Sorta. The larger goal is to have the holes in the rings perfectly aligned. That calls for quality rings AND a quality base(s), all installed correctly, which winds up with them perfectly aligned. If the bases are off, and you put good rings on them, which gives you misalignment, and you lap the rings to make them right, then it's all just a mess. Quality bases, quality rings, everything works.

Burris Signature rings have a polymer insert which can and does correct for any misalignment, and Burris Signature Zee rings fit a Picatinny rail, which is less prone to alignment problems than two-piece bases. Sako Optilock rings also have polymer inserts, if you are using a rifle with Sako tapered dovetails.

 

[BWS]

No,you don't "have" to do it.You also don't "have" to reload,choosing rigs where factory ammo is well represented.

Takes all of five minutes to make a set of alignment bars.Takes even less to make a lapping bar.Cpl minutes of time to make sure everything is straight.Why not?

 

[cdb1]

No,you don't "have" to do it.You also don't "have" to reload,choosing rigs where factory ammo is well represented.

Takes all of five minutes to make a set of alignment bars.Takes even less to make a lapping bar.Cpl minutes of time to make sure everything is straight.Why not?

So everyone has the tools to make alignment bars and lapping bars?

 

[I6turbo]

For many years (30 or so) I never lapped a ring. I also never damaged/dented a scope as far as I noticed, but I did put some minor finish marks on some. I bought a lapping kit, lapped the first set, saw how out-of-round they were, and have lapped every set since. Every ring I've ever lapped was less than perfectly round, including Leupolds and other $60-$80 rings, but especially lower priced ones. The biggest unevenness is almost always around the area where the two halves meet, mismatched by a few thousandths to several thousandths, and some definitely enough to mark or dent a scope if the rings are tightened down as much as most people do. Lapping is not essential as evidenced by the millions of sets that have been used without lapping, but I just feel better getting the rings to a round condition and being confident that they aren't going to damage or mark my scope.

Here's a set of CZ rings, which are typically pretty round compared to some popular ones, and you can see that the black finish is almost gone on the top right corner of the front ring, but the top left corner of that same ring has been cut away a decent bit and the finish is long gone. It's not as easy to tell in this "after" photo, but if you watch the metal that is removed during the lapping process (when you remove the lapping bar and check the progress) you'll see that there are clearly some high spots that would put uneven pressure on the scope tube, and as I said, some rings are off by a pretty significant margin, IMO.

 

[redneck2]

I have a really nice Burris Signature Select scope that has a crease from mounting. And I try to buy good rings. I had assumed that Leupold would be higher quality, but from the comments here that seems to not be the case

 

[cdb1]

I think they are no better or worse than most others.

 

[SamT1]

Is there any reason not to just buy a lapping bar and lap them by default. Why even check?

 

[Varminterror]

Is there any reason not to just buy a lapping bar and lap them by default. Why even check?

Checking is part of the lapping process.

Checking alignment with the pointed spindles doesn’t tell you anything about the ring contact, only where the average boreline is pointed. If they don’t line up, I shim my bases, or replace them, to gain alignment.

Checking of contact is a matter of lapping with the spindle to produce witness marks in the rings where contact is made. If contact is perfect from the box, you lap for 30 sec to remove the finish and you’ll see you do not need to continue. If it is NOT perfect, you keep going until it is. Some rings might need a LOT of work to become acceptable, some might only need a 30 second check to confirm you didn’t get the odd-man factory defect.

 

[oldfortyfiveauto]

FYI...Ruger 77 actions with the correct Ruger rings are usually out of alignment .030"
Lapping won't help that.

 

[Varminterror]

FYI...Ruger 77 actions with the correct Ruger rings are usually out of alignment .030"
Lapping won't help that.

In 30 some 77 MkII’s and Hawkeyes I have owned, and dozens more I have serviced in my shop, this has not been my experience.

 

[oldfortyfiveauto]

My latest 77 scout was so bad I replaced the ruger rail with one that extended back over the receiver to get the rings in alignment.

 

[cdb1]

FYI...Ruger 77 actions with the correct Ruger rings are usually out of alignment .030"
Lapping won't help that.

I don’t remember which order because I haven’t mounted a scope on a Ruger 77 in a while but the front and rear rings are different heights. If that’s what you are talking about it’s supposed to be that way for them to fit properly.

 

[oldfortyfiveauto]

They are noticeably different in height, but out when used correctly. It’s been that way for years.

 

[cdb1]

They are noticeably different in height, but out when used correctly. It’s been that way for years.

?

 

[oldfortyfiveauto]

Put the rings on and lay a scale in them with the top halves off. It’s real obvious then.

 

[cdb1]

The 77 receiver isn’t level so the rings have to be different heights for the scope to be level in them. It’s been awhile but like Varminterror I’ve mounted quite a few scopes on Model 77’s and never had an issue.

 

[cdb1]

Ruger OEM rings.

 

[oldfortyfiveauto]

That’s a lot more than .030” between them. When mounted correctly one will be lower. Been that way for years, up through my scout rifle when they came out.

 

[cdb1]

I’m bowing out because I don’t understand what you are trying to get across.

 

[Varminterror]

@cdb1 is on it - the Ruger M77 MkII and Hawkeye receivers aren’t flat, the front ring has to be shorter than the rear. It’s more than 0.030”, if I recall correctly, however. Something like .13”

 

[oldfortyfiveauto]

@cdb1 is on it - the Ruger M77 MkII and Hawkeye receivers aren’t flat, the front ring has to be shorter than the rear. It’s more than 0.030”, if I recall correctly, however. Something like .13”

That is correct, however when the are installed correctly the two rings are not concentric. One ring will be slightly lower than the other.