The first thing is to bore the hole properly. You can get smooth surfaces
on the outside of a turning, you can do the same for the inside of a bore
with the right geometry on the cutting tip.
After that, the ball or a rod with a large end will definietely roll over
the sharp edges but will also make the scrapes along the radius of the bore
rather than around the bore. This may be more harmful than leaving a
slightly rougher surface around the bore. Better would be to hone with
either honing cutters or stones to keep the right orientation of the grooves
that are left and get the right size for the hole.
If you're making a split bearing surface, don't forget to use Plastigage on
the bearing to make sure that it is the right clearance that you desire.
The Plastigage is available at any auto machine shop or better auto parts
store. Once you have used the stuff on a bearing and see how well it works,
you'll never go back to any othe method of checking bearing clearances.

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Why do penguins walk so far to get to their nesting grounds?