First off, the primer protrusion is about 0.040", not as earlier stated. The COAL did actually shrink by just over 0.020" but the neck grew in length approximately 0.040". As was suggested below, the shoulder was set back by the same 0.040", more or less.

Still haven't done a chamber cast but I'm feeling much better about the results from the one and only shot. I'll bump up the charge a little and/or move to a faster powder and repeat.

Thanks for the input and thoughts.