Many years ago, I was r-d'ed to be O i/c live pistol firing for a whole summer. Candidates came from far and wide, the ranges were top notch, the DIs and armourers were top notch, too.
The ammunition that was supplied lacked a certain "friction".
The rounds in question had been issued and signed for: 5 straight into the revolver, 5 to rattle around in the ammo pouch - for an eight hour shift. At the end of the shift, 10 rounds and a revolver handed back to the armourer. This occured 3 times a day! This had gone on for 25 years.
After 25 years and an incident where the bullets bounced off the bad guy's leather jacket (ISYN) , it was decided to withdraw ancient ammo and consign it to range duty.
I recall standing behind a portly WO, who favoured the "John Wayne" method of range shooting - hold it belt high, forewent the advantages of the double trigger and just cycled the hammer with his left hand. Of his 5 rounds, I saw 4 exit the barrel and land short of the 15M target!
The 9mm hi-power was quite sweet, as long as your thumb web was well clear of the cocking action!