Rifle Scopes Should I lap?

[valentin_84]

Do you guys suggest lapping scope rings? I dropped my rifle off ate the gunsmiths to have the scope mounted and I asked him if I should have the rings lapped. He said he wouldn't mind doing it but it's pretty rare that someone asks for it. I was pretty surprised. Isn't that a important thing? Should I get it done, or is it just a waist of money?

 

[LoneWolfUSMC]

Re: Should I lap?

SEARCH.....

 

[rijndael]

Re: Should I lap?

As with nearly everything, the answer is: <span style="font-weight: bold">It Depends.</span>

I would check the alignment of the rings before I blindly lapped. There are tools/kits to help with this. Wheeler Engineering is one brand.

 

[JRose]

Re: Should I lap?

I don't bother lapping mine, don't really see the benefit myself...

 

[valentin_84]

Re: Should I lap?

It seems like it would make more sense though. The more surface contact, the better right?

 

[7mmRM]

Re: Should I lap?

Yes, but you can also fuck up a set of rings by lapping too much.

I lap most all of mine. For me its cheap insurance, but I do check them first to make sure its needed.

 

[valentin_84]

Re: Should I lap?

Yeah, they are pretty high quality Farrell rings. Pretty expensive. They are made in matching sets so they may already be checked. I don't wanna mess them up because they cost so much!

 

[7mmRM]

Re: Should I lap?

<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: valentin_84</div><div class="ubbcode-body"> Pretty expensive. They are made in matching sets so they may already be checked. </div></div>

Thats not the issue. Its alignment when you mount them to the base. Reciver holes and bridge height are not always perfect.

 

[Phil1]

Re: Should I lap?

<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: 7mmRM</div><div class="ubbcode-body">Yes, but you can also fuck up a set of rings by lapping too much.

I lap most all of mine. For me its cheap insurance, but I do check them first to make sure its needed.
</div></div>

As Above;

Check engagement. I have seen very expensive rings mounted on very expensive actions-bases with limited(20%) engagement area.

Cheap insurance, check first.

 

[valentin_84]

Re: Should I lap?

Cool, thanks guys.

 

[hydro556]

Re: Should I lap?

just dont over do it

 

[LoneWolfUSMC]

Re: Should I lap?

I bed the base and leave the rings alone.

 

[hydro556]

Re: Should I lap?

You mean the lower ring that mounts to the base?

 

[ToddM]

Re: Should I lap?

I think the best way to put it is mount everything up and verify the alignment, the midwayusa alignment/lapping kit is well worth the money, and go from there. If you mount it all up and the alignment kit shows that the rings are in line, and the scope fits in them fine, then you don't need to lap. However on most factory receivers they have poor tolerances so the base bolted to them gets twisted a bit, and the rings get out of alignment. NO MATTER how expensive or perfectly machined the rings or base is. That translates to poor scope/ring contact or in very bad cases bending/denting the scope tube. Even a steel rail bends fairly easy, if you don't believe it take a quality steel base attach it at either the front or back and pull up on the other side, it doesn't take much force to flex it. Torquing the base screws can easily twist the base.

After that buy a torque wrench and properly torque the rings and bases, I'd be willing to bet that 99% of the problems people have with rings/bases staying tight and scopes moving are because they are not properly torqued evenly. It also saves you from denting the scope tube or stripping bolts/receivers by applying too much force. It's amazing how many scopes you see with brutal ring marks from guys ham fisting their rings.

For what we spend on rifles, the $80 for the alignment/lapping kit is cheap insurance, mount everything up, check the alignment, if it's good, mount the scope, torque the rings and be happy. If it's not then it's time to address possible causes, bedding the scope base, trying different rings, to get it as close as possible, then lap if the alignment is still a little bit off. If there is a major alignment issue lapping will not fix it, or if it does you may take too much material off of the rings and not be able to clamp the scope properly.

 

[SpotcheckBilly]

Re: Should I lap?

<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: hydro556</div><div class="ubbcode-body">You mean the lower ring that mounts to the base?</div></div>

I believe he means that he beds the base to the receiver. That will USUALLY negate the need to lap the rings.

One thing, though. Make sure to deburr the rings at the outside edges of the holes. Burrs in this area have caused more scratched scope tubes than anything else.

 

[TexanAviator]

Re: Should I lap?

<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: valentin_84</div><div class="ubbcode-body">my rifle off ate the gunsmiths</div></div>

RIP

 

[LoneWolfUSMC]

Re: Should I lap?

<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: SpotcheckBilly</div><div class="ubbcode-body">One thing, though. Make sure to deburr the rings at the outside edges of the holes. Burrs in this area have caused more scratched scope tubes than anything else. </div></div>

If you have to do this, you picked the wrong rings. Quality rings should already be deburred and chamfered where they need it.

Scratches on scope tubes are an operational hazard. I am guessing you will cringe when you see what I am going to do to my new SN-3 when it arrives. And I am not even going to bother lapping the rings before I torque her down.

If it gives you a "warm and fuzzy" then lap them. I use aluminum rings from a precision manufacturer on a base made by a precision manufacturer bedded to a non-precision receiver. I am not about to smear them with abrasive and grind away the hard anodizing because I am worried about marring the tube.

 

[TexanAviator]

Re: Should I lap?

Yeah, I installed my base to my receiver yesterday. Did the front two screws and lightly tapped on the rear of the base. You could hear a slight tap so there was a bit of a gap there. I could not visualy see it but I am not going to worry about it.

 

[Twisted]

Re: Should I lap?

I had a thread similar to this a week ago asking the same question. In the end I bought the Midway/Wheeler kit for $80 and did a little lapping for peace of mind. I don't see the harm in it as long as you don't over do it. I checked mine with the alignment tools before and after and lapping made an improvement for me. But others will tell you not to do it.

The piece of advice I got that sold me on lapping was from a gentleman who I know as a very knowledgeable precision shooter. He has taught me a lot and he said he laps his rings but I should do whatever I am comfortable with and will give me confidence in my rifle. With that said I lapped carefully and I feel real good about it.