This may be a silly question, but here we go. I'm going to a Can day event to try out some suppressors on different hosts. I have a few I"m leaning towards but open to being surprised by something else since there is so much to choose from. My question is this, do I have to wait until I actually purchase a can before starting the process, or can it be done preemptively to cut down on time? I'm not sure if the paperwork includes the serial number or something like that. TYIA.