Robert,

I add to what David and Doug said; the ring is made of cast iron (probably meehanite) and like a cast iron piston, needs to be annealed to reach its final size and hardness.

Start the break-in with several (10-20), very rich four-cycling short runs, (20->60 seconds each, with periods of complete cool down between them. After that, you can extend the runs to several minutes.

Do it on a test stand. This method is more time consuming, but in the long run, it will prove to have been extremely beneficial to the lifespan of the engine. The ring will last much longer than with any other method.