How do I know if I lapped scope rings too much?

[JasonT]

Hey all - sorry for posting so many questions, but I don't know who else to turn to...

I got a pair of Badger rings and 20moa pic rail a while ago and lapped them to 100% contact very quickly. They must be very precise.

But then I moved the rings to another Badger 30moa pic rail and they showed an uneven wear pattern after a quick lap...so I lapped them again using a fine valve-grinding compound (400-600grit?). Now they're at 100% again.

What do you folks think? Is there a test to find out whether i'm getting complete contact all the way around? Hi-spot blue maybe?

Thanks in advance!!

 

[Terry]

Color the inside of the rings with a sharpie. When you lap you will remove it showing % of contact.

 

[JasonT]

Yea I used blue layout dye and lapped until all of it was removed. But would lapping them twice remove too much metal?

 

[Lightload]

You'll know if the rings clamp tightly together WITHOUT holding the scope tube.

 

[JasonT]

OK - They grip tightly even without final torquing. So cool - thank you much!

 

[Ledd Slinger]

If the top portion of the rings are in full contact with the bottom of the rings with no gaps on either side where the screws are after tightening screws, you've gone too far. But it can be fixed by bedding the rings with thin shims on the bottom using JB Weld. If you have a small gap on either side after tightening the rings, you're good

 

[JasonT]

Thank you Ledd! I still have a gap on both sides.

 

[6MMsteve]

make sure you chamfer the top rings on all edges and bottom too

 

[JasonT]

Thank you Steve! I will do that!