Unregistered Firearms
The total number of unregistered firearms is impossible to know; according to some estimates, there may be as few as 50,000 or as many as 500,000. The majority of the unregistered firearms are personal war booty, Soviet or German firearms dating to WWII.
Due to changes to the legislation, unregistered firearms may now be handed over to the police without punishment for illegal possession of a firearm, provided that the owner of the firearm does so of his own initiative. The firearm is then stored while the owner applies for a permit. If he chooses not to, it will be auctioned, or destroyed if it is deemed dangerous to use due to its condition. Historically valuable weapons are sometimes handed over to museums. Un-licensed weapons may be turned over to the police, without fear of prosecution. This practice is called "mercy year", as it originally started as a one-year experiment, which was very successful. Thousands of unregistered firearms and several tons of explosives and ammunition are collected each year. Many, if not most of these items are old "souvenirs" dating back to World War II or even the Finnish Civil War.
Read more about this topic: Gun Politics In Finland