Number in barrel

[Guest]

Hello Shooters,

recently I bought an Anschütz 2013 with a 2007 stock. On top of the chamber there's a number, the serial/registration number which every rifle does have (legal one's! ;)
When cleaning the rifle I saw that underneath the barrel (the long black tube) there's also a number: 00101. There are no other stamps near. As far as I know I'm the only one in my club which has this number.

My question: can you tell me what this means or what does this indicate? Any reply is welcome!

Good Shot!