[davepl]

The bottom rail comes out when it rotates to the pin boss relief. So it's not coming out sideways like there were too much piston-to-bore, it's coming out after the ring rotates a ways and the end reaches the pin boss relief.

He would have checked all the basic clearances, so anything you'd normally mic and check with a bore gauge, etc, I can only assume was checked (I've never seen him skip a step).