Home Forums Hunting & Shooting Hunting Optics Time to lap Talley’s?

Flipping them around got them much closer with the alignment bars than the last pic, though I’m not sure I could set up the ER on my new scope with the rear ring turned around (don’t have the scope in my hands yet). After more testing after I took these pics I believe the front ring is level and the rear is the one that is off; I can turn the rear around and reverse the problem, seems to be a dead giveaway. I can’t swap the rings front to rear though. I also could not get the OEM scope bases to cowitness using the same level, so makes me wonder if it isn’t the Talley’s? Although they were much closer, may just be the position of the Talley’s when tightened down? I did try tightening them down with a solid bar covering 3 holes; I can do this on all but one screw. That got them really close with the alignment bars. After an hour of messing with it I decided to take a break; think lapping can resolve the issue? This rifle had no issues with the last scope in 1” Talley’s as far as zeroing, I didn’t check level on all of these things when I installed it.

Put the flat end of the bars together and see out of square things are. I no longer use the pointy ends.

As my posts on Tally LW's reflect, I'm not a fan, but when I use them, I lap them. I don't imagine there are too many rail options for Cooper M92's. Is that action straight across the top. I'm assuming so, if you could switch the rings around.

I'd send picks to Tally, before you lap them. I'll bet they sent you a new set of rings with nary a fuss.

This is the correct way to use the bars. Using the pointed ends will tell you nothing.

I'm convinced them pointy ends are best suited for Leupold Dual dovetails.

I am sure Talley rings come from the factory at least as true as manufacturing tolerances allow. The problem is the rifles we mount them on are not perfectly true. You most likely could take those same Talleys and mount them on another rifle of the same model and have different results just due to manufacturing tolerances at different production times, different milling machines/lathes and drill and tap operations used between individual rifles, etc. This is known in the machinist world as "stacking of tolerances". This is true even for a quality manufacturer like Cooper, who I own three of their rifles.

IMHO lapping will not resolve the issue. You will be chasing the pointed tips and not find a resolution. Can we assume the screw hole placement on the Cooper is exact? My conversations with Talley indicate they do not recommend lapping. Keep us posted on the developments.

That and f4$king up stocks.

Welp guys crisis averted...I’m not sure what physics voodoo was going on here, but I am relieved.

So I went backup to the shop after ringman’s Suggestion to use the flat ends. But this time I mounted the rings like this pic, earlier I had first tried in a way that gave me the least ring to ring distance, then inverted that. This time though I did it like this, which will be plenty for my scope and allows the most ER adjustment:



So then I did the alignment bars butt to butt...perfect. I then Used levels on the ring halves....perfect:



I then checked it using the digital level on my phone...I’m not sure why I haven’t thought to use it before. Free app. Anyhow, they are exactly level with each other to 1/10 of a degree. And I rotated the rifle a bit a few times to test, IE they both matched at -0.7, and at 1.1, etc. Torqued them down and they remained so.

Anyhow, thanks guys!

Are the recessed holes for the base to receiver mounting screw heads not finished?

I'd still lap them. They likely pinch in at the top and will mark your scope tube.

I believe I will just to protect the fragile finish on the AMG I have on the way for this rifle.

I see by the fresh aluminum on the screw holes you are radiusing off some of the base material. I see some chattering at one hole too. You need a torx with a deeper "reach" so as not to touch the top edge.

No because just recently Cooper went from 6-48 screws to 8-40. Inc guessing this was Talley’s answer for the rings they had already produced.

The fresh aluminum is from Talley, see my reply to Kingston above.

Your putting a 29 ounce scope in Talley LWs! Get a rail! A low one and some super low rings.

Nice. SMFH

You got any Birchwood Casey AlumaBlack?

I do not. It won’t bother me once a scope is mounted.

One of my failures as a person, among many, I accept