I can't fathom how chainrings can be out of round. I'm using a ring that I sawed off of a cheapo SS crank I bought for $5 (ring was fixed permanently to crankarm). I made the shoulders by sawing and filing, matching it to the spider and drilled the holes by eyeballing the holes to a road ring (lots of filing involved here, too).

I think we agree that it doesn't get any more ghetto than that. Still, it's perfectly round and doesn't tug at the chain the way I first mounted it. How manufacturers can eff this up is beyond me.

Carry on, now.