Hi Classanr ,
Yes it is a underhammer firing system. It is a double action, as you pull the ring trigger back it will retract the hammer , rotate the barrel cluster and then releases the hammer to impact the percussion cap directly on top. The hammer moves back and forth in line with the barrel. This fires the barrel positioned at the bottom center of the cluster. Makes aiming some what of a " by guess and by golly ". I personally think that this is a better system then most of the American pepperbox's that have the cap sitting on the nipple at a 90' angle to the barrel. With it directly in line with the barrel , the spent caps will fall free instead of possibly falling down and jamming the mechanism.
