When I was growing up, there was an epidemic of shooting bank robberies. The drill was for a driver to wait outside. The first guy in the door fired into the ceiling to startle the staff and customers. The firearm of choice was a cut-off carbine with a 30 round magazine. Sometimes they liked M2 carbines, which were easier to find than you'd think. He would loudly count back from 30, so the other two guys who'd leap over the counters and scoop up the cash knew how long they had. Frightening and effective. One of the official countermeasures was to change the gun rules and move semi-automatic centrefire rifles with 18 inch barrels to Restricted. And M1 carbines were the only guns that met that definition.
It sucks for the rest of us years later, but armed robbers do things differently today. Not a week goes by in any major Canadian city when a bank isn't held up.