 The Mackensens were equipped with a main battery of eight new 35 cm SK L / 45 guns in four twin gun turrets . The turrets were mounted in superfiring pairs fore and aft of the main superstructure . The guns were placed in Drh LC / 1914 mountings , which could elevate to 20 degrees and depress to − 5 degrees . The guns were supplied with a total of 720 armor @-@ piercing shells , or 90 per gun . The weapons were designed to fire 600 kg ( 1 @,@ 323 lb ) shells at a rate of fire of around 2 @.@ 5 shots per minute . The shells were fired with a muzzle velocity of 820 meters per second ( 2 @,@ 700 ft / s ) . As with other heavy German guns , these weapons used a fore propellant charge in a silk bag with a main charge in a brass case . These guns could hit targets out to a maximum distance of 23 @,@ 300 m ( 25 @,@ 500 yd ) . 
