I use a hard shell suitcase for my guns..it doesn't look at all like a gun case..... BUT..some flights Ive done within the USA involved the tagging of the bag with an extra, and easily identifiable tag. No.. it didn't say "Firearms"..but I suspect that IS one of its main uses......thus a definite "Steal ME" message.....

I cross my fingers and have Insurance..... 49 trips here to the US so far.....and nothing stolen.