The Royal Navy often ordered a lifetime supply of gun barrels

Did navies order all the replacement gun barrels a battleship class would need over its life?

It depended on the navy, but the Royal Navy often ordered a lifetime supply of barrels.

Navies did not all follow the same replacement-barrel policy. The Royal Navy commonly ordered a lifetime supply with the class. That approach protected the fleet from a production line closing before worn guns needed replacement. It also tied up money and storage capacity early in a ship's service, illustrating the logistical cost behind heavy-gun readiness.