Early Roman Republican coins were large bronze coins which were cast. However, in the later Roman Republic and the Roman Empire, the coins were struck by hand.
The coins of the period of this particular hoard are called "Antoninianii" by numismatists and represent a very debased coinage. As inflation progressed from the late Roman Republic to the later Empire, Roman coins went from high grade silver to debased silver to the final indignity of small broze coins with a silver wash, the "Antoninianus".
For a modern day Antoninianus, reach into you pocket and pull out a U.S. Quarter. :-)
u-89 , I'm a collector too. If you ever want to compare notes, Freepmail me.