Find number abc

A Microsoft support man goes to a firing range. He shoots 10 bullets at the target 50m away. Then the supervisors check the target and see that there's not even a single hit, and they shout to him that he missed completely. So he tells them to recheck, and gets the same answer. Then he put his finger at the top of the gun and shoots, blasting off his finger. When he saw it he shouted back "I don't know, it's working perfectly here, the problem must yours..."