What's the general consensus on scope ring lapping tools?

Are these thought to be at all valuable?

With the prospect of mounting a few scopes, I got one. This is the kind that also includes two bars with conical ends to align the rings.

My observation is that there are too many variables to make these work well.

In the first case, I'm using Leupold STD bases and rings. Since we drilled and tapped on a mill, I certain the bases are aligned.

But... the front ring dovetails into the base. And the rear base has windage adjustment screws. How does one know whether, if at first the two cones do not exactly align, it's an issue of (a) twisting the dovetailed ring, or (b) adjusting the windage screws?

(It does occur to me that were one absolutely anal, the receiver could once again be set up in the mill to establish the line of the bore. LOL.)

My reasoning in purchasing the lapping kit was that I had done some pretty significant stoning of the receivers, and there might be elevation alignment issues between the front and rear rings.

And the kit was on sale.

LOL.

If the lapping tool can prevent ring blems on the scope tube, that's good with me. Not to mention I think lapping is a wonderful technique to match parts up.

And I'm not averse the effort to get things right.

TIA,

flaco

Buy the Burris signature rings with the spherical inserts. They are easy to use. You can use the eccentric inserts to align the scope for elevation if needed.

I put the bases on and rest a good flat straight edge across the bases to see if they are in plain . If they are, the luepold rings will be too.

Ive never had a problem with any lueplod standard 2 piece bases except the rear base with a charger hump still on a mauser and all I had to do was file the rear base concave alittle so it was in plane with the front. It was tilted up in the front just a little.

ireload-

That sounds a lot like plan P, if I fail to be able to align the Leupold rings I have. Right now, I'm cautiously optimistic.

Rick-

Because we d/t'd on a mill, I know the bases are aligned.

Let me see if I can narrow my question down.

Right now I have the two bars with the conical points facing each other in their respective rings. The points come very close together, with the front just two RCHs higher than the rear, and the rear a little--three RCHs--to the right of the front.

My reasoning is that other than lapping, there's nothing I can do about any difference in elevation between the bases, so I'll ignore any difference in elevation. But, if possible, I'd like to adjust the rings for windage as perfectly as possible before I begin to lap.

My belief is that in general, one would normally twist the front ring in good enough for government work, and then boresight with the scope in place to adjust the rear windage screws.

I'll first ask this: When one twists the front dovetail ring into the base, does the base have some sort of detent that encourages the dovetail to align with the ring perpendicular to the bore?

If so, I'll assume the front ring is correctly adjusted.

And use the windage elevation screws to adjust the rear ring?

Does this sound like the best way to proceed? Before I begin lapping?

TIA,

flaco

N.B. I'm relatively certain the way I have bases and rings set up now will fall within the parameters of scope adjustment.

Knock on wood?

I started lapping rings about 4 years ago, after about 30 years of just tightening everything until it "looked about right". When I saw how much the rings were out of round, as well as out of alignment, I was truly surprised. I've seen quality rings where the bore of the ring was not parallel to the base. Most rings are out of round by a few thousands. Rings on a one piece Weaver base almost never line up. After I started lapping rings, I quit having the unexplainable scope problems that had given me fits for many years. All you have to do is lap one set. When you see the misalignment, you'll lap everything in sight. No pun intended.

Nashcat

There is something you can do about base elevation and I have done it a few times after getting tired of running out of scope adjustment and not wanting to use shims. I used a couple of round stones and very carefully stoned the high ring down on the underneath part of it (where it mates to the gun)to where I had plenty of scope adjustment. Then I just used a cold blue to blue it up. It takes awhile to do it right because you don't want to mess up the contour, but it works great. Just a lot of stone and try, stone and try.

I don't think the conical pointed alignment bars tell you anything. You could have a set of duel dovetail rings and turn them both 45degrees and still have the points meet. Better would be two 1" bars machined perfectly square at the ends. Butt the bars together half way between the rings and tighten the rings. If the sides of the bars aligne and there is no gap where the bars butt together, your rings should be aligned.

As often turns out, I made this more complicated than it had to be.

With the rings at their current adjustment, the long lapping bar cradled perfectly in the rings.

So I just went ahead and lapped for a while.

I could probably do a little more, but I believe I whittled down whatever gross inequities there were.

Thanks gentlemen,

flaco

Hart is absolutely correct.....in that the pointed bars are worthless.

Kevin

I do not lapp rings.
With 100 rifles playing musical scopes with 50 scopes, I standardize on Weaver rings, and no rings are lapped for some problem mount.

Instead of lapping, I get two piece mounts glass bedded into allignment with each other and the bore.

Single piece Weaver mounts are already in allignment with itself, and just need to be glassed to get alligned with the bore.

Before I shim, I bore sight to a target and shim with masking tape until the a scope is in the middle of it's vertical adjustment range. While I am doing that, I check that the scope bore sights to the middle of the horizontal range too, in case that needs correcting.

For two piece Weaver mounts, I make narrow shims like dams for the epoxy I glass bed the mount to the receiver. The epoxy must cure with the mount screws loose and the mounts held in alignment.
A scope with rings that are correctly spaced and rotationally aligned makes a good alignment fixture for the mounts while the epoxy cures. It is not easy to get the rings on the scope right. After the epoxy hardens, I take off the scope with rings and tighten the mount screws to the receiver.

That way I don't have to lapp the rings, and scopes can move from rifle to rifle, taking their rings with them.

This process is allot easier with rings that rotationally allign and tighten easily without changing the longitudanal allignment for mount spacing.

If the receiver is likely later going back into the action wrench, the glass is bonded to the mount but release agent is on the reciever. If this is not done and the mount must come off, the glass can be chipped off, but may need to be re glassed later.