.  That means that everytime you pull the trigger, the weapon will fire 0 rounds. This does not mean that you can not short stroke it and only get one, it just is the how the weapon functions when you do a full stroke retraction of the trigger. I'm not up on the mechanics, in never went to MP0 armourer school.  The HK UMP was nice when doing close in shooting, 0 rounds into a target head with a single pull was nice. Very easy to control, but it is a pistol round.  Full auto is really not that impressive until you get up into 0.00, then it becomes like a mythical weapon to smite the enemies of your nation and what not. But, I get all geeky over 0.00, especially in the M-00 version. I like it much better than any M-00 derivitive.  W