Home Forums Hunting & Shooting Hunting Optics Lapping aluminum rings

Anyone ever lapped aluminum rings? I realize you will cut through the anodize. I am just curious as to how bad the compound will embed in the aluminum, and would it really matter if it did?

i lapped a set of Talleys. i usually don't lap, but these were pretty misaligned (probably due to the reciever).

i just cleaned them up good afterwards and nothing seems amiss.

I have done it numerous times, but I'm very careful to use non-embedding compound. As for removing the anodized layer, that is helpful in that it helps you gauge how far out of alignment each ring is in relation to the other. I generally stop when it appears that I have around 70% engagement on each bottom surface.

I'm pretty sure Mule Deer wrote a very nice article on this very subject and I'm sure one of the readers will point it out. I much prefer careful lapping to reaming rings, which strikes me as a bad idea.

I lapped a set of Talleys and it made them out of round enough that it started binding the power ring on 2 different scopes.

Be vedddy careful how much you remove. Remember that if something is true and round and material you remove makes it not true and round...........................DJ

I have not had this problem, although I imagine if your lapping tool is out of round or bases are greatly askew, it would be a problem. I try to start with the rings as true to the lapping tool as possible. Some rings types are worse than others (and some are so oversized, rather than lapping, you actually have to shim from the get-go). Some receiver holes are drilled off-center too. This later problem is a real pain, particularly if you have to use Weaver rings (which should be a last resort in this case). In lieu of retapping, you then have to decide whether you want your scope to bind because of the offset or if you want to carefully remove just enough ring metal to square both rings up and relieve some of the stress.

What can happen with Aluminum rings more than others is that you end up lapping the bottoms of them quicker than the sides of the rings because they flex more easily.

Talley does NOT recommend lapping them. Lots of people do lap them anyway, I don't anymore........................DJ

When this happens, it would seem that at least 2 things are going on: 1) applying too much pressure rather than letting the tool and fine grit do the work and 2) not rotating the lapping bar while moving it back and forth.

I've not dealt with Talley's too much, so my experience is very limited with them. I doubt I've ever installed more than 4 or 5 sets and all were on guns in the .270 class. From what I recall, they were true enough that I didn't bother and never had an issue.

I lap everything, and have lapped somewhere around 10 pairs of Talleys and likely another 8 or so Weavers. Go slow, fine grit, don't overdo it.

I've never met a Weaver I didn't lap Slow and, depending on rings somewhere between 400 and 600 grit and I've never had a problem.

I decided to try my first set of Talley lightwieghts and that is what prompted me to ask the question.

I was just going to throw them on but when I started looking at them I had some doubts about them lining up. When I swapped the caps around there was a bad mis-alignment.

I lap my one piece talley's and it works well, however it does leave some alum. dust that gets worked into the scope paint. Other than that I think it's a good deal.

Spot

I've never lapped Talley LW's, but I bevel all the edges with emery paper or fine grit sand paper, and then polish edges and bearing surface with 00 steel wool.

How I do aluminum is to use very fine wet/dry sand paper over a 1 inch dowel. Don't overlap the paper, lightly clamp the ring tops to the bottoms and go slow and light. Check often. Do not remove all of the dark metal or the scope will fit loose. Do not remove enough metal that the ring halves meet one anther or the scope will fit loose. Do have the ring bottoms mounted firmly to the bases while you do this. Spin the dowel as you move it back and forth. You should be able to feel resistance, but not a lot. Push and pull the dowel, end to end. Do not push down or up or to either side. The rings should apply the pressure against the dowel, not you applying pressure from the dowel to the rings.

I noted one of the previous posters wrote they preferred lapping to reaming. 99% of the time I agree, because I think reaming torques the rings and you could possibly remove ring material that shouldn't be removed. However, sometimes the miss-alignment of the rings is so great that it would take an entire container of lapping compound to get where you need to go. I've run into this once. I foolishly waited until 2 days before a hunt to mount my optic. My plan, if you can call it that, was to mount the scope and sight it in the next day. However, the rings were so miss-aligned I would have been there all night trying to get the rings lapped in. The next day was a holiday, and all the sporting goods stores were closed, so I couldn't even hope for a miracle purchase of a set of Burris Signature rings. I elected to ream the rings I had into a rough alignment with my Clymer reamer, then I lapped the rings the rest of the way into alignment. Luckily, I didn�t run out of adjustment on my scope. But, had I put the scope in those rings without reaming and lapping, I would have probably ruined the scope.

Twas I, you are in reference to. And I do prefer it, but I have seen things so misaligned that it sometimes takes extraordinary measures like the case you mentioned. I once spent better than 2 hours lapping on a set of Ruger rings (you would have thought I could have found something better to do). I finally resorted to 200 grit, so I might as well have used a reamer for the rough-out work.

One thing I do like about lapping is that on harder kicking guns, you can increase surface contact just enough to prevent scope slippage.

I lap everything with the exception of the Near Mfg Alpha Mount. It's a unimount and is a true wonder to behold. I bed the base to make sure it isn't imparting stress to the receiver or the Alpha Mount. But, if I have two separate rings, I don't care if they were reamed as a pair. They are bolted to the base apart from each other and there is bound to be some at least small miss-alignment induced when you torque the ring down to the base. So, I bolt the rings to the base, torque them down, and then lap the rings. That way I know the rings are not stressing the scope tube. The smoothing of the surface is a bonus. Not only does it hold better, it doesn't damage the scope finish as much.

I have never used this mount. Sounds like something to check out.

I do much the same in terms of tightening the bottom of the rings. I usually like to use a one inch steel bar to set the ring bottoms, then torque them together. This helps insure initial alignment. On aluminum rings, I generally don't worry about the ring tops.

Crap...I can't recall ever agreeing with Brad so this must be the first.

Well almost, weaver rings are junk.......

Now that you mention it, I do the same thing. I position the rings in the slot they are going in, then I finger-tighten the ring nut just enough to push the clamp up against the rail. I then put lapping bar in the ring bottoms, push the rings up against the slot wall so the ring recoil lug is in full contact, and then screw the ring caps on. Then I torque the rings in place. After that I remove the caps and start lapping to determine what kind of shape I'm in. I ceased skimping on rings years ago. I had my gunsmith fabricate a 34mm lapping bar for me that will accept the handle the 30mm bar uses. All told, I have 1", 30mm and 34mm lapping bars. I don't think too much emphasis can be placed on properly mounting a scope. I cringe to think of how 95% of the scopes are mounted and bolted down "farmer tight (John Barsness, 2009)."

I e-mailed Talley a few days ago and they replied that it was OK to lap their aluminum rings.