The second case for a revolver is how we must keep the semi-auto to make sure it isn't misfired or for safety. We don't want a round in the chamber so if the gun is dropped and it doesn't have a safety against firing it doesn't go off. In addition we now have double action and single action pistols. Generally a safe way to keep your gun is no round in the chamber. The safety may even be kept on for safety. How well do people think when they have the life or death circumstance facing them? The answer is they don't think very well and it is hard to concentrate. You are in the fight or flight mode and the blood has gone to your muscles.
Will the beginner be able to remember to pull the slide back to load a shell in the chamber, will they remember to take off the safety on the pistol, and we still don't know if the gun could jam. Dislodging a jam could take some time especially when you are a beginner. Imagine a man with a knife at 15 feet away. Studies with police officers have shown an optimal distance of approximately 25 feet to draw a weapon and being able to fire in time before the assailant hits the officer and kills him with his knife. Imagine shooting and having a problem from the beginning. Is the beginner going to be able to fix that problem before the criminal gets to them. Handling a pistol requires repeated training and practice over and over again to move the slide and get the safety off to shoot in time. Your actions must be fast. The actions must be second nature or you could be dead especially if the person has a knife and is rushing you. Repeated practice over and over again so the action becomes second nature so you don't have to think about the action you just do it. This is the reason a revolver is so good for a beginner. They just have to point and shoot.
Any action forgotten or a mishap could delay the firing of the weapon. Time is critical here and you don't have minutes to decide if your gun won't fire whether a round is in the chamber, you forgot to load your gun, you forgot to take off the safety. We are talking about seconds and not minutes here. If you aren't ready to fire at that critical moment the consequences could be death. If you are more advanced you may be more ready to handle the chambering of the round, safety off, know that your magazine is loaded, and therefore respond with split second timing to get a round off.
For a beginner to get to the level where he or she has split second timing with a pistol could be awhile. My opinion here and the whys of my opinion. One more aspect not discussed here is the accuracy of the beginner because if he or she misses they could injure or kill someone else.
