brass bulging

[Vibe]

How can you ream an out of round chamber? I can see larger at the base, but not eggshaped. I'm not smart enough to do that even trying.
Butch

Strange production method involving a spinning reamer and a stationary (almost) barrel - Otherwise I would agree with you in that with the work (barrel) spinning the chamber might be off center or oversize but basically concentric.

 

[Larry Willis]

Vibe .......

Due to the cost effective methods of machining production rifles, chambers can (and sometimes are) out of round, oversized and not concentric with the bore. Sometimes it's so bad enough to see the chamber mis-alignment with a bore scope. The technique required to make an accurate rifle barrel requires much more time consuming machining techniques.

- Innovative