Lapping Scope Rings

[308win]

Is there a special tool one buys to lap rings? Could one use an old scope with valve lapping compound or toothpaste or jewelers rouge?

 

[WalkerTexasRanger]

www.sinclairintl.com

They sell a scope ring lapping kit which includes the compound, bout $20..

 

[E=MC^2]

I purchased my 30mm lapping bar through www.brownells.com.

I made my 1" bar from an AR15 bull barrel that had past the 10,000 round mark. The outside diameter was the exact same as two 1" scope tubes I had. I just threw it in a leathe and cut a few recesses to collect the compound during lapping. The recesses also act as cutting edges, I guess.