RUMORED BUZZ ON P80 GLOCK 19 GEN 3 FRAME

I am puzzled. I bought a 22lr revolver a couple weeks in the past, I planned to lengthen the barrel by about 2 inches so I asked where I could buy a substitution barrel around the manufactures Web site, they reported the gun was registered to me via the atf with a certain barrel length and if I alter which i would want a brand new serial amount.The