When American Tom Heberlein tried to import his firearms to Sweden, he got as far as his transfer in the U.K. before it started to become complicated. There, despite having the correct paperwork, a U.K. customs official said: “You can’t have these guns.”

And thus began Mr. Heberlein’s global gun education.

Although Mr. Heberlein did, after a lot of negotiation, finally get his guns through U.K. customs and in to Sweden, the entire experience created a hassle he hadn’t been expecting.

“Because I grew up in Wisconsin, I saw guns like axes, they’re a tool,” he says. “When I got to Sweden, I realized guns are way more serious than tools. Firearms have to be locked up in a safe or need locked trigger guards. You can be visited by the police and they’ll check on the guns. If there’re not safely locked up, your [gun] license can be taken away.”

Ed D’vir, principal at Protexia One Security Group, which helps Americans emigrate with their guns, says: “Exporting your guns to other countries is extremely difficult. America is very liberal, we have the Second Amendment so bringing guns into America is easier than taking them out. I usually advise people that it’s not worth the import cost and bureaucracy.”