harleypower69 said:
If airline is transferring bag to stateside leg, zero worries there.
I travel with a blade when I go to Europe. I bring an automatic Emerson. My Brit buddy told me if found it is, "straight to jail". I don't borrow trouble and never a concern coming home. Now, I don't know what style of blade you are buying but I stash mine in my shaving kit and not a word from Customs ever. If it is stashable just pack it. If having the box and packaging is crucial then ship the EMPTY box home as Customs will check all packages mailed stateside and they will confiscate the knife if it is automatic in function.
The problem comes in if the flight is delayed in London and they have to off load baggage to put people up in a hotel. Then when you go to check in for the flight...BUSTED.
The above scenario happens to people traveling with legal guns in checked baggage when their flights are diverted to New York City. With the $$$ result of dealing with the arrest and confiscation.
NOT worth the chance when for not very much money the knife can be shipped.