In 1986 I was deployed to the British Regiment and RAF Police unit in Gemany as liaison. The RAF police carried BHPs but they were unloaded. At guardmount they would draw their BHP from the armory along with a small, paper wrapped package of 10 rds of 9mm. The package was placed in the bottom of the holster and the BHP was holstered. Their SOP was if the BHP was needed they were to unholster the BHP, remove the package of 10 rds from the bottom of the holster, remove the magazine from the BHP, reholster the BHP, open the package and load the mag, unholster and load the BHP. The packages were examined at the end of shift. If worn or torn the package was opened, rds counted, and then re-wrapped.
Sound silly? Along with the BHP the RAF Police also carried 9mm Sten with the mag loaded and inserted. It was not uncommon for one of the guys to have an AD getting out of a vehicle or going thru a door. They'd catch the charging bolt on something which would pull it back just far enough to pick up a round and chamber and fire it. IIRC the penalty for an AD was $200 plus a weekend of extra duties. They had to account for every rd in the mag at turn in.