Scope Ring Honing

[AIM STR8]

After having the scope rings honed in and properly torqued down I got to wondering what are the chances that the center of the scope and the center of barrel are not co-planar?

Any experience with this?

 

[bluegrassdan]

Just curious, but was there a reason you lapped your rings?

 

[AIM STR8]

Just curious, but was there a reason you lapped your rings?

 

[bluegrassdan]

Wow, that's pretty bad. That's also a lot of material to have to remove to get them to line up. Run the risk of oversizing the interior of the rings enough that even torqued properly, the scope might move under recoil. Might want to get a witness mark in pencil on the tube to verify it does not move for the first few rounds.

 

[Wind Gypsy]

After having the scope rings honed in and properly torqued down I got to wondering what are the chances that the center of the scope and the center of barrel are not co-planar?

Any experience with this?

As long as it you’re not way off from center of scope adjustment range, what is your concern?

 

[AIM STR8]

Wow, that's pretty bad. That's also a lot of material to have to remove to get them to line up. Run the risk of oversizing the interior of the rings enough that even torqued properly, the scope might move under recoil. Might want to get a witness mark in pencil on the tube to verify it does not move for the first few rounds.

I don't think it was as bad as it looks

 

[AIM STR8]

As long as it you’re not way off from center of scope adjustment range, what is your concern?

Same concern you would have to glass bed the action .... free float the barrel, etc.

 

[Wind Gypsy]

Same concern you would have to glass bed the action .... free float the barrel, etc.

I'm not following. Those have to do with not inducing stresses in the action or barrel and thus impact consistent performance round to round. What you're talking about is just a matter of angular adjustment of the scope within the designed adjustment range.

 

[AIM STR8]

I'm not following. Those have to do with not inducing stresses in the action or barrel and thus impact consistent performance round to round. What you're talking about is just a matter of angular adjustment of the scope within the designed adjustment range.

Lapping can increase the amount of surface contact between the ring and scope tube, and also help with proper alignment between the scope rings.

 

[Wind Gypsy]

Lapping can increase the amount of surface contact between the ring and scope tube, and also help with proper alignment between the scope rings.

People know what lapping is. You asked about center of scope and center of bore being co-planar, that is a different topic especially once lapping has corrected any notable misalignment of rings. What is your concern about center of scope tube and center of bore not pointing in the exact same direction if that difference is reasonably close to the center of a scopes elevation/windage adjustment?

 

[scub300]

Burris sig Z rings pretty much eliminate this problem.

 

[bluegrassdan]

I doubt you would lose much, maybe a 1/4 minute or couple of tenths out of the adjustment range even if it was now off the same axis. You did not change the rings by a large degree angular wise, you just changed the surface area more than anything (unless you were pushing really hard on one end during the lapping stroke). I have seen some crazy results of people trying to lap everything to be 100% cleaned up and then wonder why things move.

 

[AIM STR8]

People know what lapping is. You asked about center of scope and center of bore being co-planar, that is a different topic especially once lapping has corrected any notable misalignment of rings. What is your concern about center of scope tube and center of bore not pointing in the exact same direction if that difference is reasonably close to the center of a scopes elevation/windage adjustment?

Lets be fair .... you were the one that moved the conversation to "lapping". All I was asking is for those that have "lapped" in any scope rings if there was any negative results. I don't have any concerns so to speak of other than I like things to fit properly.
Lets leave it at that.

I'm a retired Tool Designer and worked in a shop that dealt with tolerances that most places would not deal with or be able to achieve. I acquired a penchant for precision fits as a result of that.

 

[AIM STR8]

I doubt you would lose much, maybe a 1/4 minute or couple of tenths out of the adjustment range even if it was now off the same axis. You did not change the rings by a large degree angular wise, you just changed the surface area more than anything (unless you were pushing really hard on one end during the lapping stroke). I have seen some crazy results of people trying to lap everything to be 100% cleaned up and then wonder why things move.

Thank you sir, That is the kind of answer I was looking for !

 

[AIM STR8]

Burris sig Z rings pretty much eliminate this problem.

I used those on another rifle of mine and took very little to clean them up.

 

[howl]

I used those on another rifle of mine and took very little to clean them up.

What did you find to clean up on Burris Signature rings?

 

[Walkathon]

I think you're fine. I lapped more than that off a set of rings and everything worked fine. The rifle sighted in with no problem, and it holds zero, really well. I used what appears to be the same kit with the honing bar, lapping paste and the two pointed shafts to check alignment in all planes.

 

[AIM STR8]

What did you find to clean up on Burris Signature rings?

I don't recall exactly, I couldn't find any pics that I took

 

[Richard22]

Not an expert at all in this area but it seems lapping scope rings when they're attached to a two-piece base creates more benefit than when attached to a one-piece base. The lapping process itself seems to be an effort to wear away small imperfections in the shape of the rings and alignment of the base screws. Same as allowing rod bearings to "bed" with a crankshaft.

What I find interesting is how Leupold and perhaps others machine ridges into their rings to create a better fit, ridges that are at least partially worn away during the lapping process. Are these ridges added in order to reduce the need for lapping?

 

[WapitiBob]

Lets be fair .... you were the one that moved the conversation to "lapping". All I was asking is for those that have "lapped" in any scope rings if there was any negative results. I don't have any concerns so to speak of other than I like things to fit properly.
Lets leave it at that.

I'm a retired Tool Designer and worked in a shop that dealt with tolerances that most places would not deal with or be able to achieve. I acquired a penchant for precision fits as a result of that.

Biggest issue I have seen is the ring mounting system doesn't ensure both ring sets maintain concentricity, which is the issue when mounting bars don't line up. Lapping the rings in unison to then get both ID's concentric can easily oversize the id or at least a ring half radius.
There is also the possible issue of lapping bar OD plus lapping compound thickness.
I use a rail, checked for flatness on a rock and sweep it, then bed the rail and use cross bolt rings to get the best initial setup I can, then dbl check with a very light lap and look at the anodizing contact.