German Rail Gun

[Flying10uk]

Does any-one know what sort of life the barrels of these 800mm (80cm) guns had i.e. what sort of number of shells on average were the barrels capable of firing before they needed replacement. I seem to recall hearing or seeing somewhere that the barrels of these massive guns had a very short life. The barrel would have been difficult, time consuming and expensive to manufacture and then difficult to actually transplant onto the actual gun.