Ok guys! I've made up my mind! I'm getting/building my first SBR. Friday I am ordering an LMT complete lower, when I get it, I'm starting the paperwork. I have one question still. This spring I'm planning on buying a house. When I move, what do I have to do while the paperwork is being processed? Do I just notify the ATF of my new address so they can contact me that way? Plan is to go with a 10.5 or 12.5" upper for now, then start paperwork of a suppressor and shorten the barrel to around 7.5". Might as well ask one more question. Can I switch calibers on a registered SBR? Say start with 5.56 now then put a .300 upper on it someday?