I have travelled back and forth, (with approved ATF form) with my trailer carrying my powder, primers, bullets, rifle and whatever else I can get in there about 20 times a year for the last 15 years with "never" a problem from either side. Re the letter of invitation, the NBRSA blanket letter, thanks to Don Creach and myself will get you the ATF form, but I would strongly suggest that you get a invitation letter from the range itself and carry it with you. I, and others have been asked for an invitation from the range itself. Anyone going to WWCCA can get their letter from me. That letter can Emailed, Faxed, or snail mail as long as it is a piece of paper that says you are invited. What I do with WWCCA is list the name of the person on a club letterhead with a list of all the matches for that year and send. Now here is a bit of information you can use or not, your choice, "DON'T LIE" only tell them what they have asked you, and very little more. Example; do you have loaded rounds in your vehicle. Yes, there might be 25 or more back there somewhere. And something I learned 30 years ago, what weapons do you have. I have 2 "SINGLE SHOT TARGET RIFLES" Lenny went across a couple of years ago and had a Customs Officer want to see the rifle. Well Len opened the back of his truck and showed him the rifle and the guy like OOOO, AAAA picked the rifle up and started trying to look through scope. Of course this guy is swinging it around and there a car of, immigrants behind him and they were dodging for cover. Len got through but had to pull over because he was laughing so hard. Anyway they are not after you, Oh 1 more thing do not have the bolt in the rifle, put a trigger lock on the rifle and make sure the case has a lock of some sort on it. I know you don't have to but try telling that to a Customs guy who is doing a cavity search on you. All you need is a bit of common sense and no smart talk.