cartride chamber clearance

[sam m]

I'm trying to find out if the chamber of my
new barrel is oversized. I know that cases vary, but on average how much side to side clearance should an un-fired cartridge have in the chamber?

[Rule .308]

You know, it's as I figured but I had to get up and check a few chambers to be sure. There shouldn't be enough play there to even speak about. Using my highly calibrated "eye"crometer I'd have to say it's somewhere in the ten thousandths (.0001) and not the thousandths (.001) range. I measure stuff in this range often enough to know it when I see it and I'd have to say my guns are in the .0001-.00015 range. This is all based on dropping an unfired '83 Cavim in an StG an Israeli and an L1A1 and inspecting to see how much side to side play there is in it. Hope this helps.

Rule .308