Mains Current Monitoring


I'm in the process of building a new power controller for my coils.  The
question I have is on measuring input (mains) current which can be up to 50
amps.  I'd prefer to do it without utilizing a shunt.  Can I build a current
transformer by taking a toroid core, wrapping one turn of a primary leg
around it, then winding 100 turns around it for a secondary, and hooking the
secondary to a .5amp meter? 

What other ways are available to measure this level of current (50 amps)?
Should I reconsider using a shunt?

Thanks in advance,
Brian B.