The two remaining "Adolf-shells" in the Adolf Gun bunker in Harstad, Norway. These shells were much lighter (600 kg) than the normal shells (1030 kg) used by the four 400 mm Adolf guns to allow a longer range of 56 km (versus 42 km). The maximum ceiling in the ballistic trajectory was 21,000 meter (70,000 ft) or twice as high as a passenger jet flies. This gun was built by the Germans in WW2 in Harstad, Norway, but never fired in anger. The gun was operated by the Norwegian armed forces in the 1950s, the largest gun ever used by the Norwegian armed forces.
<a href="//commons.wikimedia.org/wiki/User:Orcaborealis" title="User:Orcaborealis">Orcaborealis</a>
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<span class="int-own-work" lang="en">Own work</span>