Yes, the m/45 is a relatively simple, blowback operated, 9mm submachine gun that fires from open bolt and itīs relatively easy to train people with no military background to use this weapon. It was the standard smg in the Danish armed forces for many years. I myself have fired this weapon a few times. Excellent weapon with reasonable accuracy.
During the Vietnam War, the US Navy SEALs used the Carl Gustav m/45 SMG extensively, including with suppressors, because it can fire immediately out of the water. The m/45 is a higly reliable weapon and will operate under extreme conditions such as arctic cold and desert heat. According to Danish SOF, who sometimes still use the weapon, you can soak the m/45 in mud, sand and snow - clean it by rinsing it a puddle of water, and it would keep firing.