What it seems to be is this:

Governments sign up to CIP (which, you are correct, is primarily interested in safety).

The Proof Houses were set up by Act of Parliament to govern the safety of small arms. They act with a Proof Master in charge, answerable to a board.

Rules of proof have been issued over the years to take into account changes in gun making and ammunition.

Presently, the proof houses are having to enforce the CIP directives imposed on all members.

One question is whether introduction of these CIP dimensions is an improvement. I think it is arguable.

Another question is how are the proof houses implementing the rules? This is the main issue currently under investigation.

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