Avoiding ring marks on a scope?

[BoydAllen]

Gabe,
For a Panda type action, get a Kokopelli lapping bar (comes with compound) mount and lap your rings, to the point where the cutting pattern shows that you are finished. Next, take a small fine file, or coarse diamond lap, and round off all of the corners and edges, at the cap parting line, that will come in contact with your scope. After that, clean the inside of the rings, starting with a light oil, and then switching to something to remove that. You should clean with the oil till no more color from the lapping byproducts shows on the paper towel. Then you can mount your scope. Aluminum is my favorite ring material, for situations where I am not using the Burris rings. It is plenty strong, and easy to lap. I have done this several times. The most exciting time was when I was mounting three March scopes for a friend who I was working for at the time. All of the jobs came out just fine, as well as several others that involved less expensive scopes, and less nerve racking situations. With full contact, you don't need to get carried away tightening the ring caps on the scope. Afterthought: When I am lapping the rings, I do it with the caps off, sitting so that I can put them back like they came off, after bottoms of the rings are finished, I drag each cap down the bar, till the cutting pattern shows that they are correct, debur the same edges and corners, clean them , and then mount the scope. It usually takes very little lapping of the caps, since they have not been distorted by tightening onto bases, but I have run into one pair where a little strategic bending was indicated by the cutting pattern. The caps were being cut excessively near the inside of their parting lines, and a little careful flexing (These were very thin aluminum caps.) made for a much better fit on the bar, and a lot less lapping than would have been otherwise required. Caps will self align to the scope tube, so I see no need to try to lap with them in place. I am not aware of any steel rings that are used on Panda's so I will skip bedding rings, but I once lapped a set of Stainless Ruger rings for a friend, and that experience is a good reason to favor bedding steel rings.
Boyd
Boyd

 

[p-man]

Advice and WARNING for those lapping for the first time:

(BTW, if you have a pair of old rings, especially aluminum ones, it is always advisable to practice first.)

1) Before disassembling your rings the very first time, take a sharp pointed piece of steel (I use a old jewelers file with pointed tip) and scribe marks on the INSIDE of the rings - start on the top half and continue the mark downward to the other half. I do one mark on the left-hand side on the front ring and two marks on the left-hand side of the rear ring. Scribe/scratch deeply enough that the marks are still visible after lapping. If you lap properly, you will be doing it carefully in stages, removing the top halves and inspecting the rings - this will ensure that the ring halves always go on the right way and are not mismatched. (Don't worry about the rough edges of the scratches - they will be polished out by the lapping process.)

2) I loosely mount the rings on my lapping bar as an alignment guide before mounting the rings on the base(s) or rail. You should be able to tell right off if the rings and the mounts are off or grossly out of alignment. If you are using Weaver or rail-mount, tactical rings and things are way off, lapping is not the answer - double check both base/rail and rings and make sure. I've seen some sorry sh_t from these third-world importers. Lapping won't correct for 10 thousandths of slop.

3) THIS IS VERY IMPORTANT: As much as possible, try not to put any DOWN force or any LATERAL pressure on the lapping bar - it takes more effort to NOT do this - remember that the bar itself weighs a couple of pounds. Rotate the bar as much as you can moving it forwards and backward - if your hand gets tired, that is when you will screw up - take a break, this isn't a race - any downward force will tend to cut or lap the bottom half rings out of round. I lap both top and bottom halves of the rings - I very gently tighten the rings so that the lapping compound tends to ooze out. I always tighten the rings in very careful, GENTLE increments as I work the bar - if you're not careful, you'll eat up a pair of aluminum rings and they will be oversized. (If you have or can borrow a micro-torque wrench, always ensure that you follow the manufacturer's suggested settings when tightening base and ring screws.)

3) DO NOT BEVEL RING EDGES FIRST! It is quite possible to leave protruding, jagged or rough edges on the surface that you just lapped. What I do is wait until it looks I need one last time to get an even lap pattern (for me that means no high sides or black spots remaining) - this is when I file the radius edges of the rings as well as the inside straight edges where the ring halves join - I actually sand with high-quality finishing paper (320 for aluminum - 220 for steel) using a wooden dowel for backing. Then I do the final lapping and all is smooth as a baby's butt - rest assured that there will be no rough edges to scratch your scopes.

4) What should be mentioned is that more importantly than protecting the finish on your scopes, lapping ensures that whether you mount $2000 or $200 optics, when done this way they are completely aligned in the rings and STRESS-FREE - many would be surprised to realize how many scopes are actually bending or bent when mounted incorrectly - and then again most don't have a clue about the stress harmonics receivers are subjected to during recoil - especially with heavier calibers.

5) I've used Burris Signature rings and will continue to do so on light calibers - still not sure how straight and stress-free they are when tightened down. I've either bedded or mounted bare scopes in lapped rings - I'm intrigued by the "hockey tape" and think that may be a real time-saver.

Anyway, this site is about helping each other so I hope that maybe I have helped save someone a set of rings.

 

[Uthink Uknow]

On a benchrest rifle with Kelbly rings, just wipe the edges of the rings (top and bottom portion) with emory cloth and be done with it. That seems too simple.

 

[BoydAllen]

Have you read the part in Tony Boyer's book about scope mounting? What seems like elaborate care to me, comes up as quick and dirty when compared to the lengths to which he goes. Of course, what does he know?

 

[JRS]

Have you read the part in Tony Boyer's book about scope mounting? What seems like elaborate care to me, comes up as quick and dirty when compared to the lengths to which he goes. Of course, what does he know?

It was Tony and Skip Otto who showed me the rubber cement trick 8) They picked it up from a technician who worked for Bausch & Lomb many years ago.

 

[shooter65]

For the win!

burris signature zee with the delrin inserts, or lap a "quality" set as previously suggested.