Which Scope Ring Lapping Tool?

[Buano]

You'll like it.

Maybe you know this already but a couple of thoughts....

I put "drop rags" over my action and other parts when lapping to avoid getting any compound down into the action or anywhere else. I also mark the rings with a Dremel at the mating surface by one of the ring screws so I know which ring is front and which one is back, and which side is then left and right. A very tiny dot for the front left, and 2 dots for rear left, with the dots on both the upper and lower halves and I can identify any part if I ever take it apart again without having to worry about ring alignment or lapping.

The rings will have compound on them after the process. Be sure to clean them off thoroughly.

Have fun!

Thanks, I hadn't thought about marking the rings. That makes sense.

 

[deepstuff]

So, should the lapping bars be exactly 1" and 30mm or should they be slightly undersized?

 

[WapitiBob]

Don't over lap and also get some "ring tape".

 

[Trickymissfit]

So, should the lapping bars be exactly 1" and 30mm or should they be slightly undersized?

Better grades of drill rod, and not the Chinese stuff, will run about .001" under size. Same for standard grade Thompson Rod. precision grade is spec'd at .0005" under size. Most drill rod is just rough ground. I wouldn't be afraid of .001" or even .0015" undersize, as the size will open up slightly even if done carefully.
gary

 

[deepstuff]

Better grades of drill rod, and not the Chinese stuff, will run about .001" under size. Same for standard grade Thompson Rod. precision grade is spec'd at .0005" under size. Most drill rod is just rough ground. I wouldn't be afraid of .001" or even .0015" undersize, as the size will open up slightly even if done carefully.
gary

So how undersized should it be?

 

[Trickymissfit]

So how undersized should it be?

I would go .001" undersize, and try it out on an old set of rings. The one thing I don't like about Thompson rod is that it's hard (62RC+). Ideally, I'd rather have something a lot softer, but also very round and strait. A piece of ground finished 8620 (also to the needed size) would be about perfect as it's somewhat porous and has a 15rc. Hopefully the compound would embed into the metal better. But there's a much better way to lap rings if you have access to a lathe.
gary