In article .com,
says...

The instructor has us do a
180 so as not to intrude on the Class C improperly.


I've done that too - I would certainly not enter a Class C under the
pretext that I was talking to Center. However I've never had the
unpleasant surprise of not getting handed off in time. If I did, I would
tell Center something like "remaining clear of class charlie until
established with approach" or something like that, while drawing circles
in the sky.

GF