Compatibility among 13.5-inch ammunition types

Did the Royal Navy use two non-interchangeable types of 13.5-inch ammunition?

Not as wholly separate Royal Navy systems; several ammunition types existed, and some could be used across systems after limited modification.

Royal Navy service did not divide 13.5-inch ammunition into two wholly incompatible systems, although other weapons of that calibre could present compatibility problems. The British used several ammunition types rather than one uniform round. Limited modification could allow one type to work with another. Compatibility was therefore a matter of degree rather than a simple yes-or-no distinction.