I have two SBRs, but in thinking about the best way to include a short "long gun" on our travels I've decided rather than fill out the ATF paperwork I'm just going to build a pistol lower from one of the stripped lowers I have in the safe. The states I'd be traveling in include Oregon, Washington, Utah and Montana. I'm assuming this is what most folks do? Of course if I need to use an SBR in a match, let's say the Area 1 Steel Challenge championship (which was in Montana this year) I'd have to file (form 20?) with the ATF, but for travel the pistol seems the way to go: 30 rounds of defensive 9mm on hand with spare mags.