lapping bar size?

[earlcurtis67]

If you were to make you're own scope ring lapping bar, what size should it be? 1.00?
a little under, say .990 ? or a little over, say 1.010? thanks E

 

[FearNoWind]

I'd make it precisely the size of the tube of the scope I intended to mount. No pinch, not bind, no slop.

 

[Trickymissfit]

If you were to make you're own scope ring lapping bar, what size should it be? 1.00?
a little under, say .990 ? or a little over, say 1.010? thanks E

I made several of them out of left over pieces of Thompson Rod. The stuff is hard, and round & strait. Use the standard grade and not the precision grade. It will be just about .001" under size. I also done it with drill rod, and the results are similar. Ideally, I think .002" undersize would be best. Might get there with some of the cheap grades of drill rod.

DO NOT use lapping compound!!!! It will embed in the rings and ruin the scope tube on down the road. Somebody sells a "non charging" lapping compound, and it just washes out of the metal with a little lighter fluid. Comes in a yellow powder form, and you mix a little bit in three in one oil.

gary

 

[bruce_ventura]

1.000, +/- .003 is what I use. Drill rod works fine. The lapping compound will increase the diameter about .002. Most rings also flex a little when tightened, so a final ring diameter within about .003" of the scope tube diameter seems to work well.

...DO NOT use lapping compound!!!! It will embed in the rings and ruin the scope tube on down the road. Somebody sells a "non charging" lapping compound, and it just washes out of the metal with a little lighter fluid. Comes in a yellow powder form, and you mix a little bit in three in one oil. gary

I agree, solvent wiping doesn't completely remove lapping compound from the ring. I've found that lapping compound does comes off with Scotch tape, however. I first clean the ring with alcohol. I then lay a piece of tape over the lapped surface, press it in with my finger, then pull it off. Repeat and all lapping compound is gone.

I always use RingTrue tape after lapping. http://www.highpoweroptics.com/ringtrue™-tape-three-scopes-p-24944.html

 

[Ridgerunner665]

Thanks for the tip on the tape...hadn't heard of it before but it looks like something I can believe in for $10 (to save a $1,000+ optic)

 

[earlcurtis67]

All good sugestions fellas, thanks E

 

[J E Custom]

I am one of those guys that don't like to lap or ream scope rings because it is very easy to screw
them up.

First , I would recommend going to a smith that has the tools and has done this.

Next , I would recommend that if you have not done/tried this "don't" without the proper tools.

Then , If you still want to do it buy a Scope ring reamer (Some where around $100.00). It is much easier to use and will make the ID of the rings true and round. anyone that has used them can tell you the correct way and save you time and the cost of a set of rings.

Lapping is not an exact science and can do more harm than good IMO. and in many cases not necessary if the rings are aligned properly in the first place.

I was always worried about marking expensive scopes, not to mention the possibility of flexing
the scope tube due to improper alignment of the rings so I started trying different ways to prevent this.

Lapping was one of the ways, then reaming and then I started trying different methods of installation that would align the rings before the scope was installed.

There are different techniques for different bases but rarely if done correctly, do I have to reject a set of rings and bases. I have never used my lapping bars or reamers on a scope install after testing
was done and if a set of rings will not align, I replace them.

If the replacement rings are/were not available in a timely manor and I needed them fast I would resort to reaming them.

J E CUSTOM

 

[Trickymissfit]

1.000, +/- .003 is what I use. Drill rod works fine. The lapping compound will increase the diameter about .002. Most rings also flex a little when tightened, so a final ring diameter within about .003" of the scope tube diameter seems to work well.


I agree, solvent wiping doesn't completely remove lapping compound from the ring. I've found that lapping compound does comes off with Scotch tape, however. I first clean the ring with alcohol. I then lay a piece of tape over the lapped surface, press it in with my finger, then pull it off. Repeat and all lapping compound is gone.

I always use RingTrue tape after lapping. RingTrue™ Tape for Three Scopes

I see where your going, but doubt your getting 60% of the compound from out of the rings. The stuff I spoke of is hard to get because of it's chemical content, but it's still out there. Two ounces will probably do a hundred rifles.
gary

 

[Edd]

How thick is that Ring True tape?

 

[earlcurtis67]

JE has brought up an interesting point about scope ring alignment that has got me thinking. When i install the bases (weaver) i only screw down the bolts lightly to allow the bases to move and align themselves to the scope but stay put while removing the rings and scope. then tighten and torque the bases. This only solves the problem of perpendicular (?) alignment but not horizontal. What if you used short studs instead of the base screws, set the bases over the studs, then install the rings and scope, then much like a rail or one piece base you could check for horizontal misalignment of the bases to the reciever. Then if needed, bed the bases or base that is out.
I realize this may be overkill, but lapping or reaming would not be nessesarry, or at least minimize it. I also realize that the quality of the bases and rings will go a long way to minimize misalignment, but we cant do anything about the condition of the receiver or the alignment of the reciver screw holes
If anyone has a better or simpler way to align two piece rings rings, by all means......E

 

[bruce_ventura]

How thick is that Ring True tape?

0.0025", including the adhesive. After lapping the rings are usually about 0.002" oversize, and most rings flex about the same amount. When using RingTrue tape the scope tube fits a little snug but the tube can still be moved back and forth and rotated.

 

[bruce_ventura]

I am one of those guys that don't like to lap or ream scope rings because it is very easy to screw them up. First , I would recommend going to a smith that has the tools and has done this. Next , I would recommend that if you have not done/tried this "don't" without the proper tools. Then , If you still want to do it buy a Scope ring reamer (Some where around $100.00). It is much easier to use and will make the ID of the rings true and round. anyone that has used them can tell you the correct way and save you time and the cost of a set of rings. Lapping is not an exact science and can do more harm than good IMO. and in many cases not necessary if the rings are aligned properly in the first place. I was always worried about marking expensive scopes, not to mention the possibility of flexing the scope tube due to improper alignment of the rings so I started trying different ways to prevent this. Lapping was one of the ways, then reaming and then I started trying different methods of installation that would align the rings before the scope was installed. There are different techniques for different bases but rarely if done correctly, do I have to reject a set of rings and bases. I have never used my lapping bars or reamers on a scope install after testing was done and if a set of rings will not align, I replace them. If the replacement rings are/were not available in a timely manor and I needed them fast I would resort to reaming them. J E CUSTOM

Going to a gunsmith for every scope install just isn't practical for a lot of shooters. If someone has just a few rifles and a gunsmith nearby, sure. Most folks are almost forced to do it themselves. The right tools make it possible to get consistently good results.

I'm not a gunsmith, but I install lots of scopes. In addition to installing scopes for HighPowerOptics, I run scope clinics at local ranges twice a month. I see a wide variety of rifle, base, ring and scope combinations. In most cases, I have to work with what I'm given, rather than starting fresh with premium bases and rings. I usually reject cheap Chinese rings. The screws and threads often fail when torqued and the ones with thick fabric tape on the saddles loosen over time because the tape is compressible.

I agree that getting the rings aligned properly in the first place is the best practice. With steel rails and heavy tactical rings this is usually all I do. However, most target and hunting rifles I see have lighter weight rails and rings, or two piece bases. I usually bed aluminum rails and lap the rings. I install two piece bases as best I can using a steel ruler and feeler gauges to align the bases. I use Kokopelli alignment bars to check ring alignment. I will shim and bed one or both bases if necessary to get a good vertical alignment. This is a time-consuming process that rarely produces perfection. After that I still lap the rings. The reason I always lap is that lower cost (<$100) rings usually have extruded saddles that are not perfectly round like fully machined rings. Going with fully machined rings certainly avoids a lot of these issues. I just don't see the point of paying $150+ for expensive tactical rings when lapping $50 rings produces the same or even better results.

I have reamers, but usually prefer to lap. I find that reamers are a little touchy and require a lot of care when tightening the rings. It's easier to take off too much material with a reamer. I use Kokopelli lapping bars because they're long and give reproducible results. The lapping process is slow and gives me ample opportunity to inspect the rings during the process. While lapping is not as precise as reaming, neither are scope tubes all the same diameter. I've never ruined a set of rings by lapping them, but then I make sure the rings are close to aligned before I pull out the lapping bar. This is probably a Ford vs Chevy kind of discussion. I can certainly see how one could feel more comfortable reaming over lapping.

 

[J E Custom]

JE has brought up an interesting point about scope ring alignment that has got me thinking. When i install the bases (weaver) i only screw down the bolts lightly to allow the bases to move and align themselves to the scope but stay put while removing the rings and scope. then tighten and torque the bases. This only solves the problem of perpendicular (?) alignment but not horizontal. What if you used short studs instead of the base screws, set the bases over the studs, then install the rings and scope, then much like a rail or one piece base you could check for horizontal misalignment of the bases to the reciever. Then if needed, bed the bases or base that is out.
I realize this may be overkill, but lapping or reaming would not be nessesarry, or at least minimize it. I also realize that the quality of the bases and rings will go a long way to minimize misalignment, but we cant do anything about the condition of the receiver or the alignment of the reciver screw holes
If anyone has a better or simpler way to align two piece rings rings, by all means......E

+1

That is part of my procedure. (Never tighten the ring to base screws more than hand tight to allow the rings to fit/align themselves to the scope.
I also machined a 1" and a 30 MM rod 10"long to check alignment before placing the scope in the rings. It will assure that the rings and bases(Horizontal and vertically) are aligned.

If not, I replace them. If there is a difference in the receiver height, I will do a stress free bedding of the base.

"NOTE" I have no room for aluminum rings and bases in my life after one to many failures.

And the cheaper bases are prone to be sloppy and misaligned. I believe in buying good to best quality rings and bases and don't mind spending $100.00 plus to prevent damage to a very expensive scope rather than cut corners and cost and risk damage to the scope. If you buy cheep rings and bases you will most likely have to spend more than the difference in the cheep and good mounts just to save the cheep mounts.

On hard recoiling rifles cheep scope mounts can/will fail at the worst time, so you don't save any money buying them and in the long run you will probably spend more.

It doesn't make sense to buy a $400.00 dollar set of rings and bases for a $200.00 dollar scope on a $300.00 dollar rifle, But on a long range rig, I consider a good to best set a must.

PS there is no such thing as over kill if it will improve the accuracy and dependability of you investment.

Just My Opinion for what it is worth.

J E CUSTOM

 

[earlcurtis67]

Thank you Bruce and JE for you're explanations.....E