This may sound like a simple answer (and that's because it is a simple answer) but often the simplest answer is the right answer.
My answer is this: in 3 Gun competitions you should shoot the same caliber pistol that you predominately carry in real life. The reason is simply that you want to gain as much experience shooting your chosen caliber for real life. Every time you shoot a firearm, muscle memory is further ingrained into your nervous system. And whatever habits you acquire shooting in high stress training scenarios are the habits that will come through in a real life high stress scenario.
This is not unique to shooting. This is true of all physical training adaptations for skills that involve high speed and automatic responses that are intimated by habit rather than conscious thought.
If you shoot with a 9mm in competition, your body will get very accustomed to the muzzle rise of a 9mm and the tempo at which you can shoot double taps. The more you do it, the more automatic it will become. If you then turn around and try to shoot a .45 cal in a high stress fast paced scenario you will find your rhythym is completely off and you may even shoot worse than you would have if you had never trained yourself in fast paced scenarios to begin with.
Now this is not to say that mastering multiple calibers cannot be done. There are plenty of professional competition shooters who have achieved this to a world class degree in fact. However, for these guys, shooting is a 100% full time job. The number of reps that they can get in for each caliber in a week is more than most hobby shooter will shoot in 10 years.
For most of us, picking one caliber for high stress shooting and sticking with it is the wisest choice.
Like Bruce Lee always said, "I would rather fight a man that knows 10,000 punches than a man who has practiced one punch 10,000 times." Pick your punch, and master it to the utmost.
What if your carry pistol is a .45? Is it going to be nearly impossible to win 3 Gun competitions shooting a .45 cal? Well, yes it is going to be difficult to beat a bunch of guys who are shooting 9mm if you are shooting a .45 in a 3 Gun competition. But you have to ask yourself why you're shooting 3 Gun. Is it to win, or to train yourself to be better so that you're prepared if you ever need to actually use your firearm in a real life or death high stress scenario.
The answer to that question should be what ultimately determines the decision for you.
My answer is this: in 3 Gun competitions you should shoot the same caliber pistol that you predominately carry in real life. The reason is simply that you want to gain as much experience shooting your chosen caliber for real life. Every time you shoot a firearm, muscle memory is further ingrained into your nervous system. And whatever habits you acquire shooting in high stress training scenarios are the habits that will come through in a real life high stress scenario.
This is not unique to shooting. This is true of all physical training adaptations for skills that involve high speed and automatic responses that are intimated by habit rather than conscious thought.
If you shoot with a 9mm in competition, your body will get very accustomed to the muzzle rise of a 9mm and the tempo at which you can shoot double taps. The more you do it, the more automatic it will become. If you then turn around and try to shoot a .45 cal in a high stress fast paced scenario you will find your rhythym is completely off and you may even shoot worse than you would have if you had never trained yourself in fast paced scenarios to begin with.
Now this is not to say that mastering multiple calibers cannot be done. There are plenty of professional competition shooters who have achieved this to a world class degree in fact. However, for these guys, shooting is a 100% full time job. The number of reps that they can get in for each caliber in a week is more than most hobby shooter will shoot in 10 years.
For most of us, picking one caliber for high stress shooting and sticking with it is the wisest choice.
Like Bruce Lee always said, "I would rather fight a man that knows 10,000 punches than a man who has practiced one punch 10,000 times." Pick your punch, and master it to the utmost.
What if your carry pistol is a .45? Is it going to be nearly impossible to win 3 Gun competitions shooting a .45 cal? Well, yes it is going to be difficult to beat a bunch of guys who are shooting 9mm if you are shooting a .45 in a 3 Gun competition. But you have to ask yourself why you're shooting 3 Gun. Is it to win, or to train yourself to be better so that you're prepared if you ever need to actually use your firearm in a real life or death high stress scenario.
The answer to that question should be what ultimately determines the decision for you.