My understanding is that a company by the name of Century International Arms contracts with various ammunition manufacturers to produce ammo with that brand name.
Much of it is made by Privi Partizan, but a lot of their .223 is made by PMC.
So with it coming from different sources, I'm going to guess that it's going to vary in quality from batch to batch.
Check it over close and make sure if it's Boxer or Berdan primed, before you break a decap pin.