Mr. Laidler - your single-shot SA80 experience in 1993

[Sentryduty]

Deactivated firearms, if done to the standard are considered non-firearms like any other similar weighted item of metal.

That standard seems to evolve from time to time but is no where near as rigorous as proofing like the UK.

Of course if the deact were used in a criminal manner it stands to reason a suspect might be charged as though it were a live gun.