As a member of the EU it’s straightforward to take a rifle with from the U.K. to Europe, specially if travelling by car. I have a European Firearms Permit which allows you to transit a number of countries with no bother.

How does it work for visitors who are from outside the EU? So if in the future if take the ferry to Holland and then travel to Germany will I have to get lots of different permits?

For Sweden you have to have a permit for temporary import of weapon.


https://polisen.se/en/laws-and...ms/temporary-import/

If you travel thrue the Netherlands you need an "consent" it will be free issued by dutch customs(douane)
But you have to get the consent online, better aske for it some weeks before traveling!