I read somewhere of some holding the trigger back when chambering a ctg. so the rifle's bolt is uncocked, with a round in the chamber. To fire, simply raise the bolt then lock it down, aim and fire, sort of a double safety.
I assume that is what they are talking about & no, it is not a Canadian 'thing'. I read that in Guns and Ammo, or Shooting Times - one of those, maybe Guns.