I've noticed that the smith who reamed my .458win out to .458 Lott has scratched the chamber, about halfway down.
The rifle is dissassembled at the moment since I wanted to bed and reinforce the stock before I started shooting with it, but now I'm wondering what kind of effect the marks are likely to have on the rifles accuracy or extraction.
I suppose it will be impossible to tell without shooting first, but really, shouldn't the ream job be flawless?

Scratches in the chamber are usually the sign of someone in a hurry or who is not paying attention to the little details. About the only way minor marks such as these, assuming they are minor, will affect accuracy may be in the psycological effect it may have on your ability to hold a tight sight picture while seething over a less than perfect chamber job.

It would take some fairly heavy damage to affect extraction. Shoot it and see what it does.

I'm with Westpac on this. I got a chip in one of my BR chambers up by the shoulder. It left a small ring that ended up .001 deep. It shot great but was hard to extract after 3 firings on the brass. I cut .250 off and rechambered it.
Butch