You'll be fine with your film in carry-on. Ask for hand inspection if you're really really concerned, but don't make headlines if you hear a no.
Once the number of gates I pass hit double digits per trip I switched to buying locally and processing as I go. Before that I used lead-lined bags. 6 gates max without lead, Europe only, 400 ISO, no issues.
I've never had a problem in the USA asking for a hand check. When questioned about worrying about ISO 400 film I just tell them 'but I shoot it at 1000, not 400, and stand develop in Rodinal' (True). Their eyes glaze over but they hand check, and are always quite polite when doing so. (I'm quite polite when asking too.) Rather unlike the lady in Frankfort security who asked me to turn on my Nikon F and I told her I couldn't. :)
Shoulda told her "It's mechanical. It's always on." :)