GLOCK 43X P80 FRAME CAN BE FUN FOR ANYONE

I am confused. I bought a 22lr revolver a few weeks ago, I planned to lengthen the barrel by about 2 inches so I asked in which I could buy a substitute barrel over the manufactures Web-site, they said which the gun was registered to me from the atf with a certain barrel duration and when I alter which i would wish a fresh serial quantity.Again to