When Bandidos and Hells Angels had a falling out in Denmark and Sweden a few decades ago, missile launchers, heavy machine guns, hand grenades, car bombs, just about everything was put to use.
Edit: Despite loosening up recruiting requirements considerably, the bikies eventually made peace when they started dying faster than they could recruit.
Edit2: The army depots the article refers to were a left over from the cold war that was still only a few years in the past. National guard units had depots all over the country to make mobilization of reserves faster in case of DDR and Polish troops invading.
Cut and paste from Wiki (Great Nordic Biker war)
Weaponry
Between 1994 and 1997, there were at least thirty-six break-ins at Swedish and Danish Army installations; at least sixteen Bofors anti-tank missiles, ten machine guns, around three-hundred handguns, sixty-seven fully automatic rifles, two-hundred-and-five rifles of various calibres, hundreds of hand grenades and land mines, and seventeen kilograms of explosives plus detonators were stolen. Police believe the Bandidos or their support clubs were responsible for the majority of the thefts. The Hells Angels obtained Russian- and Yugoslavian-made rocket launchers as well as surplus machine guns and rifles from East European countries.[6]
The conflict saw the use of the Swedish AT4 eight times, and the Russian RPG-22 three times. Hand grenades were used four times and a booby trap once. Car bombs were utilized three times, while other types of explosives were also used on three occasions. The bombs used scaled in size between one and five kilograms.[6]