I have a gun out for delivery to my LGS today. Since I had to go to town, I stopped buy thinking I could fill out the BGC form whether the gun had arrived or not. The fella that was working told me I couldn't do that because the serial number had to be on the form first. I told him that it made no sense to me and I really didn't want to make another trip to town. I have to make another trip to town. Is there a logical reason for him not allowing me to fill out the form?