If I remember correctly a Norwegian rifle club held up a German Parachute Regiment causing so many casualties that the German Para's had to pull back and regroup.
Perhaps a bit exaggerated, but the myth is partially based on a true story, or stories.
Rifle clubs were found all over the country, and they were a part of "the voluntary shooting association" founded by the government in 1893, it was a civilian association but recieved a great deal of support from the military, and it was based upon the idea that the members would be better trained for military service and defense of the country.
The grain of truth mentioned here is from the "battle of Midtskogen" where elements of the 1. Royal Guards Company and volunteers from the local rifle club set up a roadblock and fought a sucsessfull battle against a "company" (about 100 soldiers) of German Fallschirmjäger.
But the rifle clubs did pull their load on several other places too, Valdres is one palce often mentioned, but Narvik was the place where the "regiment" of German paratroopers entered the story.
As many of the soldiers in the Norwegian 6. division was locals, most of them was naturally attached to a local rifle club, and many of them brought their own rifle when they were mobilized.
It should be noted here that both the army and the organized rifle clubs were using the same primary weapon, the Krag Jørgensen rifle in cal. 6,5x55.
The only difference being that the rifle clubs often sported more accurate sights, and the owners knew their rifle like the back of their hand.
Taken into consideration here that target-shooting, both practise and competition, back in those days was done on dostances ranging from 200 to 600 meters, depending on what discipline they were competing in, the number of long-distance head-shots became remarkable high on the Narvik front.
And the Germans was forced to pull back and regroup a number of times, the last incident being when the commander, general Dietl, had to face the possibility that he had to either surrender, or withdraw his force over the Swedish border and risk being interned by the Swedes.