Not sure what your getting at but whenever it has gone through with the bags I clearly tell them there is film in an X-ray proof bag. I hold out the bag to show them when I request a hand inspection. They have never rerun the film without the bag and usually go to hand inspection if they care for it. A number of times it has gone through with the bags no problem.
I think the point he's making (which was my experience too when I last used a lead bag - decades ago), Newt, is that if the screener sees a "black blob" they will not assume that it is film and therefore OK... they will assume that they cannot assess the situation and either re-scan in hopes of a "better angle" or pull the bag out for hand check. That hand check may be performed primarily to figure out what is being concealed more than to be nice to the guy carrying film. When that has happened to me, the entire contents of my carryon have been examined rather than just the "black blob". You appear to have had better success with your lead bag than have others. :)
p.s. When I last used lead bags and told the screener that I had film in a lead bag I got one of two responses: "hand it to me and I'll handceck it for you", or "remove the film from the bag and put both separately on the conveyor". Not enjoying this experience an dhaving never had a problem with xray damage no matter where I've flown... I gave up on the lead bag many years ago. I'd much rather glide through the security stations without ever having to interact with the security personnel.
I guess to each his own then. Traveling without the xray bags is much lighter, and is what you should be doing if you wont be in an area with lodging or a car for a bit of time and have to be on foot. I have also heard that the radiation from longer flights may actually be more than what is experienced from the burst of xrays from the scanner, if thats the case maybe the bags help with that too.
I've recently developed HP5+ pushed to 1600 which went through quite a bit scanning (at least 4 if not more) and I see no damage on the negatives. Same result with tmax 400 @400.
I prefer to avoid any hassle with airport security, specially in the countries which might be considered "hot". I would actually consider both, Jordan and Egypt to lean towards the "hot" side at the moment.
In both countries you can also expect your baggage is going to be scanned at the hotel (at least they did it in my hotels in both countries) on each entry. Better put the camera around your neck before you enter.
Sorry for digging this up, but while the hand-check vs. carry-on scan battle still rages (and doesn't interest me), I get the impression that film in checked bags is a very bad idea?