Moose,
the Korean-manufactured PMC .223 ammunition is a side line of the factory that also makes ammunition for the Korean military and far eastern markets. The factory was set up under Winchester-Western technical advisors, I believe.
Those crimped-in primer pockets are standard for MILITARY-SPECIFICATION ammunition in 5.56mm NATO (.223), 7.62 NATO (.308 Winchester), and .50 BMG calibers. The primer crimp serves to prevent primers backing out in full-auto fire guns and causing jams.
Yes, the fired cases ARE reloadable, but you need either a primer pocket swaging tool (used in your sizing press), or a hand-held primer pocket reamer to cut it out. You can do a job with a sharp pocket knife, but it's a lot of work.
Other than the primer pocket crimp, the brass is perfectly good for reloading.