 The main battery was supplied with a total of 720 shells or 90 rounds per gun . The guns had a rate of fire of around 2 @.@ 5 shells per minute . Post @-@ war tests conducted by the British Royal Navy showed that the guns on Baden could be ready to fire again 23 seconds after firing ; this was significantly faster than their British contemporaries , the Queen Elizabeth class , which took 36 seconds between salvos . The German weapons were , however , less accurate than earlier German weapons , and fired a lighter shell than the equivalent British guns . The German armor @-@ piercing shell weighed 750 kg ( 1 @,@ 653 lb ) and was driven by a 277 kg ( 610 @.@ 7 lb ) RPC / 12 propellant charge in a brass cartridge . The shells were fired at a muzzle velocity of 800 mps ( 2 @,@ 625 fps ) . Each gun was expected to fire 300 shells before replacement of the barrel was required . The guns that had been constructed for the battleships Sachsen and Württemberg were eventually used as long @-@ range , heavy siege guns on the Western Front , as coastal guns in occupied France and Belgium , and a few as railway guns ; these guns were referred to as Langer Max . 
