Kelbly rings/lapping

[goodgrouper]

I don't know if this is posted in the right spot but here she goes:
I just bought some Kelbly 30mm rings and have read that they are CNC machined so well that you don't have to lap them. Is this true? Mine look good, but not that good.

 

[jb1000br]

[ QUOTE ]
I don't know if this is posted in the right spot but here she goes:
I just bought some Kelbly 30mm rings and have read that they are CNC machined so well that you don't have to lap them. Is this true? Mine look good, but not that good.

[/ QUOTE ]

LAP EVERYTHING!! It doesnt matter how straight the rings are if the action isn't perfect.

JB

 

[sakofan]

I'm no the other side of the ring lapping issue. Dont lap nothing!! /ubbthreads/images/graemlins/grin.gif

A few ring marks on my scopes wont make me go out and buy a lapping bar. But, hey that's me!!...sakofan....YMMV, of course. /ubbthreads/images/graemlins/wink.gif

 

[chris matthews]

Most lapping bars are made out of cold rolled steel and are plus or minus the width of your hand on tolerances (meaning they are not 1" or 30mm exactly) and will wear from the lapping compound. Plus scope tubes have a plus and minus tolerance also. So you decide......but Kelby is pretty decent stuff so you shouldn't have to.

 

[goodgrouper]

Thanks guys for your input! /ubbthreads/images/graemlins/grin.gif

 

[daveosok]

I disagree.
If your slapping Kelby rings on a rem 700 action you should (and highly recommended) lapp the rings as the outside diameter of the rem action is turned using a belt sander spun between rods or on a rod by hand.
I recently decided to cylindrically grind the outside dia of my rem 700 to make it concentric to the bolt bore.
It took .011 thou of grinding to produce a cleaned up outside diameter. It was tapered .0055 /ubbthreads/images/graemlins/shocked.gif. Now that may not seem much but to a machinist like myself thats a load of room and will produce non centered rings imparting stresses into your scope. I guess it really depends on what scope your using too, if your sticking a 100 dollar trascho on it then dont waste your time but for me and my Leupolds and Nightforce scopes Im not spending 1k and then bending it to fit the rings.
JM2C

 

[goodgrouper]

Thanks Daveosok. I kinda figured they still needed to be lapped, but what do you think about it if they are going on a Speedy Gonzales sleeve that is supposedly straight in line?

 

[TOM H]

Doesn't Speedy make rings for his sleeves?

 

[daveosok]

If your using inserts that align the bore of the rings then your ok. Rings should be lapped if you suspect they do not line up perfectly.
I just purchased a Bat action. You can rest assured it is very accurate and striaght but the mounts and rings are a separate piece.
Its a little like when you chamber a barrel. Shilen makers of very high quality barrels even get there bores off center a few thousands. Whats a few thousands, well if your threads arent concentric with your bore then they will be off center consequently everything else will be off center. You wont find hardly any high quality gunsmith not indicating a barrel bore in to assure that the bore is centered not the outside diameter.
Same thing goes with rings and bases, why pay good money for the gun and the rings and the scope only to impart undue stresses on your scope and for those who are benchrest shooters your also imparting stresses into the action but this is to the extreme end of things.
I plan on making my own mounts and rings. Once I secure the mounts and rings the inside diameter will be left small and I will wire edm the correct diameter for a 30 mm tube. This wire edm will cut to within millionths thats 5 decimal places past the decimal and I will still lapp them to final dimensions.
The scopes also must be measured as they have tolerences and 1 inch or 30 mm could be 1 or 30 mm +/-.005 which would impart the wrong clamping action.
If the dia is to small then it will try and force the wings of the rings outwards and I suspect that this is a better condition than the diameter being bigger and the scope only contacting the bottom and top center of the rings creating a dangerous stress causing flat spots on the top and bottom of the scopes diameter and may cause the owner to over tighten to prohibit slippage.
I wont get my diameter perfect nothing ever is, but I mesure each of the scopes and make a lapping mandrel per diameter and use diamond lapping compound of 9 and 3.5 microns which takes a bit more time to lapp but leaves a superior finish and removes as little of the base material as needed for a smooth and centered finish.
This may sound over the top but I believe that whatever errors you can remove from your weapon the least you have to deal with when troubleshooting problems and propper scope mounting will allow one to search for other areas in the weapon that may cause inaccuracies. If it is extreme in the area of damage to the scope some scope manufactures may void the warentee due to owner neglect.
Just a suggestion but call one of the scope makers and ask them what they recommend it would be interesting to hear what they have to say anyway. /ubbthreads/images/graemlins/confused.gif
JM2C
Dave /ubbthreads/images/graemlins/wink.gif

 

[sakofan]

Not be sound argumentative, but why spend a bunch of money on a custom stick, high end scope, and then turn around and buy rings, that NEED to be lapped in order to work properly? /ubbthreads/images/graemlins/confused.gif

Buy Badgers, and Marty will tell you in no uncertain terms, not to lap his rings.
As a matter of fact, lapping the rings will void the warranty.

I don't hold all the answers, and please don't be offended. My knowledge pales in comparison to most here.
But,why not just buy Badger rings to start with?? You can't get a better product...IMHO..sakofan.....

 

[daveosok]

I can say this with absolute certainty. If your action I.E. Remington is the action being used I don't care how accurate your rings are the action isn't.
Yeah Marty rings are superb I have a set and yes I lapped them.
The Remington action diameter is approximately 1.350 in diameter; the drop in distance for the rear scope base mounts is according to blueprints is .118. You're using approximate measurements with precise rings and you're expecting them to line up perfectly?
I used a coordinate measuring machine, a device that uses a probe to measure dimensions and it is very accurate and one of the only ways to measure some dimensions.
The drop from the front scope base area to the rear scope base area on this particular action was .11975. Now if Marty's rings and bases are made to account for this exact figure then they will most likely line up but I doubt it as the actions are belt sanded while spun on a rod by hand. Do you think the outside diameter of such an action is straight doing it by hand?
I don't think so and not even the most experienced smith or machinist would tell you that hand forming is one of the most accurate ways of bringing in a dimension.
So lets say Marty's rings are based off .118 which I've seen a section of the blueprints for the rem 700 and it happens to be .118, you have a difference of .00175 that still means they don't line up despite Marty's excellent product.
So why lapp rings that don't need to be lapped is clearly explained here with the inaccuracies of manufacturing deficiencies.
More often than not the actions are a lot more out than one would expect and I refer you to my other post where I mentioned the .011 thou clean up it took to get the action parrelle this would have meant that the .118 dimension was indeed something completely different with the .0055 taper per side and once again reaffirming that exact rings dont make exact scope mounts as the actions arent exact either.

 

[sakofan]

Roger that.

Good info there...sakofan..Thanks.

 

[Skinny Shooter]

Daveosok, I can see what you are saying about that drop from front to back.
Would the standard scope base screws have enough strength to torque out of alignment my Badger 20moa 1-piece Base?
If they don't, is that point then moot when using a heavy-duty Base like Badger?
In my photo it appears that the Base is made to counter-act that height difference.
Thanx

 

[goodgrouper]

Sakofan,
Badger rings would have worked fine, but I already had the Kelbly's so I used them. Kelbly's rings are coming with inserts too, but only in 1" size I guess. My scope is thirty of course. How come I always want want they don't make?!