Actually I did not really see it very well ... I was on the range between some dozen other shooters, so I simply pointed the gun in the direction of the targets when I blew that ball out... A very short blast with the CO2 discharger gave a jetlike 'mist' out of the barrel that extended aut for about a yard. I guess it was condensation from the escaping gass...
Afterwards I tried to find the bullet but i did not find it in the grass.
I was amazed how easy and quickly it worked, and I only had to swab the barrel and load again for the next shot.