lapping kit?
- Thread starter souther33
- Start date
silvrjeepr
New member
I can say that the two sets of rings that I lapped were misaligned. One slightly, and the other pretty badly. In fact, the reason I bought a lapping set was because of a moving scope. This fixed my problem, and I doubt I'll ever mount another scope to two piece rings without lapping first.
All my scopes are mounted using Wheelers Scope Mounting Kit: includes Lapping bar for 1" and 30 mm, Aligning bars for both sizes, Wheeler "Fat Wrench" for torqueing all screws properly, and 220 grit lapping compound.. And we use it religously, and we dont have any scope problems.. never..
silvrjeepr
New member
I have heard that if you lap the rings too much, you can make the rings too loose to hold the scope. i've never seen this for myself though. Someone would have to be insanely heavy handed and work a long time to get to that point. The neigh sayers normally just say that lapping isn't needed or isn't as precise as the factory machining. I suppose they're entitled to their opinion, but was completely sold on the process after my first set of rings. Give it a try and see for yourself.
Jeeper, you would have had the worst case of "tennis elbow" before you could truly lap that much material out... There are scope ring reamers that also intend on aligning that will harvest too much material, be aware of those dudes, but 220 lapping grit isn't over aggressive...
When the scope rings are mounted they're pretty much impossible to get absolute pure perfection, thus a little help from the Wheeler kit, I have installed 9 scopes so far and no problems have been incountered.
I must say though, like my handloading procedures, I tend to stay right by the book when mounting scopes.... Therefore No Problems!!
When the scope rings are mounted they're pretty much impossible to get absolute pure perfection, thus a little help from the Wheeler kit, I have installed 9 scopes so far and no problems have been incountered.
I must say though, like my handloading procedures, I tend to stay right by the book when mounting scopes.... Therefore No Problems!!
If you dropped it and it lost 0, this is caused by cheap mounts.
Many, most low dollar mounts will do this because they do not have the strength to resiste ther force of even a light drop.
Buying a quality base and ring set should fix this. Generally, around here this is hard to find at the big box stores and most LGS.
I think the Leupold PRW or Warne products are good basic mounts, but I own neither to be sure.
I own TPS and Larue base with TPS rings on my AR and hunting rifle. These are top end and too much for most rifle systems.
Many, most low dollar mounts will do this because they do not have the strength to resiste ther force of even a light drop.
Buying a quality base and ring set should fix this. Generally, around here this is hard to find at the big box stores and most LGS.
I think the Leupold PRW or Warne products are good basic mounts, but I own neither to be sure.
I own TPS and Larue base with TPS rings on my AR and hunting rifle. These are top end and too much for most rifle systems.
Personally- and this is pure conjecture (maybe a smith that has done hundreds would know..) I think it's likely more of an issue where you have rings separately mounted directly to the front and rear of the receiver, as opposed to rings mounted on a pic rail, or a one-piece set.
I think it's very unlikely when dealing with precision machining done with quality rails and rings for there to be issues of tolerances of any consequence. OTOH, if the receiver was d&t'd for two-piece mounts, I find it reasonable for there to be measurable variances that could benefit from trueing.
I think it's very unlikely when dealing with precision machining done with quality rails and rings for there to be issues of tolerances of any consequence. OTOH, if the receiver was d&t'd for two-piece mounts, I find it reasonable for there to be measurable variances that could benefit from trueing.
Lapping is needed if the bases aren't well aligned, but most factory drilling and tapping is quite good...some not. It can be checked by laying a scope on the mounts, then pushing on it from the top of each mount, to see if it rocks on one mount. I often use a lapping bar to do the same thing, then proceed to lap to see how much they are out of line.
If you dropped your rifle, you could have damaged the scope, especially the either end that impacted the ground. My son's rifle was knocked onto the floor by his dog and it bent the objective end to the point he missed a deer five times at 40 yards.
Another person asked me to drill and tap his .22 rifle and install bases, but didn't bring the scope. When he got home, he called and said the bases were misaligned, so I asked him to bring the rifle and scope. The scope had a huge ding in the objective where it had been dropped. The bases were aligned okay.
If you dropped your rifle, you could have damaged the scope, especially the either end that impacted the ground. My son's rifle was knocked onto the floor by his dog and it bent the objective end to the point he missed a deer five times at 40 yards.
Another person asked me to drill and tap his .22 rifle and install bases, but didn't bring the scope. When he got home, he called and said the bases were misaligned, so I asked him to bring the rifle and scope. The scope had a huge ding in the objective where it had been dropped. The bases were aligned okay.
reynolds357
New member
I used to lap, but now Burris Signature rings are just so much easier.
reynolds357
New member
Trublu, you bed the rings or the bases? I have never heard of bedding rings.
I bought a 1" diameter piece of SS rod stock, verified it had no run-out, and just set it in the rings before tightening them up. Use a sequential tightening method and I've been good to go. I tighten the rings while the mounts are still a bit loose on the rail, then tighten down mounts to a uniform torque. No problems with my Leupold and Burris optics.
Hobie
Hobie
both - although you only need to do the lower half of the rings. And of course i use a torque screwdriver on all the screws
here's an example
here's an example
A place I used to work had Swiss turning machines.They feed in bar stock through precision bushings.The bar stock is precision ground on the OD .005 under nominal,so 1 in nominal stock is .995,and 30mm stock would be .005 under 30 mm.I was fortunate to snag some bar ends headed for the scrap bin.
Grit sizes are screen sizes,so 1000 grit is approx. .001 rocks,100 grit is approx. .010 rocks.With 320 grit and a .995 bar I can get pretty close to 1.000 dia.
Receivers distort a bit in heat treat,bases and rings have tolerances.
That is with modern rifles..go back to milsurp sporters with bridges altered,etc...It is worth paying attention.
I have seen a number of bases where the contour to match the receiver was visibly wrong,the radius edges were tapered.
This may seem extreme,but I set the lower rails of the receiver on parallels on a granite surface plate,and I use a test indicator and height gage to verify base heights assembled to the receiver.More often than not,I end up using a boring head in a mill to remachine the underside of the bases so the surfaces the rings clamp to test out aligned to less than .001 .
Then I will lightly lap the rings,watching the bluing on the rings disappear.
Read the scope mfgr's literature.Most of them will brag a little about the tolerances they hold internally on the parts and alignments
They may use numbers like .0004 in
The scope is a thin tube,usually aluminum,and it is flexible,not a solid steel rod.
If your rings are not aligned,but your mount system is strong,what happens inside the scope as you white knuckle down on those screws?
The tube bends,and all the tight tolerance alignments and fits you paid for go away.
On vintage scopes,lenses were laminated with balsam.
Now,super glue and loc-tite are used in assy.A little too much flex,pop!
Precision adjustments? Ever used up 40 rds chasing groups around a target trying to get a 100 yd zero? Hmmm.
"slight ring marks" Hmmm.
I might put as much time and effort into properly mounting a scope as I do fitting a barrel.
I do it because I can,and I'm not paying anyone.It works.
Grit sizes are screen sizes,so 1000 grit is approx. .001 rocks,100 grit is approx. .010 rocks.With 320 grit and a .995 bar I can get pretty close to 1.000 dia.
Receivers distort a bit in heat treat,bases and rings have tolerances.
That is with modern rifles..go back to milsurp sporters with bridges altered,etc...It is worth paying attention.
I have seen a number of bases where the contour to match the receiver was visibly wrong,the radius edges were tapered.
This may seem extreme,but I set the lower rails of the receiver on parallels on a granite surface plate,and I use a test indicator and height gage to verify base heights assembled to the receiver.More often than not,I end up using a boring head in a mill to remachine the underside of the bases so the surfaces the rings clamp to test out aligned to less than .001 .
Then I will lightly lap the rings,watching the bluing on the rings disappear.
Read the scope mfgr's literature.Most of them will brag a little about the tolerances they hold internally on the parts and alignments
They may use numbers like .0004 in
The scope is a thin tube,usually aluminum,and it is flexible,not a solid steel rod.
If your rings are not aligned,but your mount system is strong,what happens inside the scope as you white knuckle down on those screws?
The tube bends,and all the tight tolerance alignments and fits you paid for go away.
On vintage scopes,lenses were laminated with balsam.
Now,super glue and loc-tite are used in assy.A little too much flex,pop!
Precision adjustments? Ever used up 40 rds chasing groups around a target trying to get a 100 yd zero? Hmmm.
"slight ring marks" Hmmm.
I might put as much time and effort into properly mounting a scope as I do fitting a barrel.
I do it because I can,and I'm not paying anyone.It works.