Why British autoloader research is difficult to reconstruct

Were the papers for British capital-gun autoloader projects destroyed or otherwise lost?

The surviving record is very incomplete; researchers know more papers existed but have not yet located them.

Surviving papers appear severely limited even where researchers know relevant records once existed. Researchers are therefore hunting for documents whose former existence can be inferred but whose present location is unknown. The gap makes it difficult to determine how far particular British mechanisms progressed beyond design discussion. Claims about the exact maturity of the capital-gun autoloader work must consequently remain qualified.