Borrow scope lapping tool???

[ar15barrels]

The plastigage thing is for bearings, which are supposed to have a certain clearance. Scope rings aren't supposed to have any clearance.

Plastigauge will show angular misalignment very well though.

[ar15barrels]

Did you read somewhere this was a good idea? The point of lapping is to have even contact along the whole surface of the ring. The plastigage won't tell you anything about that because if there are high spots, you won't be able to tell. Those high spots won't compress.

I take it you have not used plastigauge.
It will absolutely tell you if you have misalignment.

[ar15barrels]

If the flattened plastigage isn't uniform in it's spread I'd attribute that to imperfections in the machining of the rings.

29 times out of 30, the problem is the base being twisted on the reciever, not the ring machining.

[ar15barrels]

1. What is 'Scope Lapping'?
2. Why is it done?

The use of a mandrel and abrasive (lapping) compound to correct misalignment within the rings to eliminate angular misalignment stress on the scope tube.

It's a "hack" fix for parts that don't fit correctly to begin with.

[LWP]

I lap all steel rings! Does it do any good, I don't know. But it eliminates the possibility. Shooting to me has a certain about of head games to it, so eliminating every variable I can just helps my head.

Got into a debate with a Leupold tech about lapping rings when I asked if they could supply a 34mm lapping bar. They tried to tell me their rings were near perfect and did not need lapping..... Really....

After having a 34mm bar ground from an old rail gun barrel, I lapped the 34mm Leupold rings, they were not round and had high spots.

I have lapping bars for 1" 30mm, & 34mm.

Pay the shipping and promise to return it, you can borrow it.

The 1" and 30mm were cheap to make, just order the bar stock from McMaster Carr and a handle. The 34mm was a different story, had to have one ground.

Drill a hole, tap, screw in the handle and you are ready to go.

I lap with four different compounds, 300 grit, 600 grit, 1200 grit, and Ultra Bright Tooth paste.

I can post a picture of what I made when I get home if you would like, they are easy.

PM me if you want to borrow mine.

I agree with you, if you have the tool and are able to do it, which is very simple, why not. It only makes sense, especially after you start lapping for a few minuets and confirm from the results where the high and low points inside the rings are. And if there aren't any you'll know quickly and can stop. No harm no foul.

[boyguan]

Hitting steel at 1000 was easier than I thought. All this work isn’t needed if your goal is a24x24 at 1000

[Mute]

If it ain't broke, don't fix it. Shoot your set up first and see if it actually performs as needed.