It teaches you weapon preferences through first hand experience...
By that I mean that it reveals to you REAL quickly which of your weapons is easiest to shoot fastest, load fastest, and be most accurate with...
That's right, you guessed it...its the rifle
...every single time.
The movies may often make pistols out to be sexy, cool, etc, etc but heck, the movies can't get anything about guns right at all. Half the time, the pistol goes DOWN rather than UP when a shot is fired from it. How ridiculous. It is hard for me to even fathom how that has gotten by all these years in Hollywood. There's always so much talk about Hollywood trying to make movies more and more realistic, etc, etc. Well if you want to make things realistic, how about starting out with something super simple and easy? Like just making a muzzle rise rather than fall when a shot is fired.
Anyway, back to the subject, pistols are nice to have for one very simple, practical reason: they are small and easy to carry.
Plain and simple, if rifles were as easy to carry as pistols, there wouldn't be much reason to have pistols. But the reality is that its simply inconvenient to carry a rifle around all the time wherever you go. They're heavy, they're awkward, and they would get in the way of nearly everything you have to do during your day to day activities and work.
But aside from the convenience for carrying aspect, if you had a choice between a pistol and a rifle when choosing a weapon for maximum effectiveness, there is absolutely no question that the rifle is the superior choice many, many times over. Its not even a close call. It is as obvious as the fact that a glass of water is better at quenching your thirst than a glass of milk would be.
However, oddly enough, this obvious reality somehow doesn't actually seem to be widely known.
I once read a story about a cop who usually kept his AR-15 in the trunk of his car and merely had his pistol and 2 or 3 extra magazines in the cab with him. (you can see where this story is going already can't you?)
Anyway, all in all, if I remember correctly, he had somewhere around 55 rounds available on him at all times. So here he was driving down the highway with nothing but his pistol and 55 rounds within reach.
He hears the description of a vehicle for a fugitive, looks up and sees the guy driving two cars ahead in lane next to him. The fugitive sees him and cuts across traffic to make and exit. Finally, after chasing him through a neighborhood, the guy pulls over, jumps out and start firing at the cop. The cop fires back of course and hits him multiple times but the guy doesn't go down. I can't remember if the cop ended up diving under the car or what, but in the course of events the cop reloaded his pistol multiple times and hit the fugitive multiple times and he still never went down.
Finally the fugitive ran out of ammo too and sprinted back to the cab of his car grabbed another pistol and turned and continued to shoot at the cop. Finally, the guy went down at this point.
After it was all over the cop goes and looks in the cab of the fugitive's car and there is a loaded SKS rifle laying on the front seat. He was absolutely dumbfounded (and also obviously eternally grateful) that the fugitive grabbed another pistol instead of the rifle when he went back to the car. And for that matter, why he chose the pistol over the rifle the first time he got out of the car. He could have ended that cop's life in one easy shot instead of dying in a shootout if he had simply picked up the rifle instead of a pistol.
I have often thought about this story and what it means.
Obviously, the cop learned a strong lesson and he always carries his AR-15 in the cab with him now and also carries over 150 rounds of ammo with him now instead of only 55.
However, aside from that, the fact that the fugitive grabbed a pistol instead of a rifle as his choice of a weapon TWO separate times.is absolutely inexplicable....UNLESS, UNLESS he literally just did not know that a rifle was a much better choice, many many times over.
This made me think, I wonder how many other people don't realize how obvious of a choice this is? How many people have acquired the majority of their gun knowledge from movies and, as a result, literally have no idea that a pistol should be the last weapon on the list of preferred firearms.
Only a few first hand experiences will teach you this without a doubt. However, if it happens to be a life or death situation, you may not get the chance for another first hand experience if you don't get extremely lucky during the first one.
Think through just a few of the factors:
Again, back to 3 gun...
If you shoot 3 Gun regularly, no one needs to tell you these things. No one needs to tell you that, hands down, the rifle is nearly always the ideal small arms weapon of choice.
You simply know this because you've shot and reloaded each type of weapon as rapidly as possible in a pressured situation dozens of times and you know that no matter how fast you can load a shotgun, its still super duper slow. So slow, its ridiculous. Makes you feel like you're living in the 1850's or something.
No matter how accurate you are with a pistol, every single super challenging pistol target would be an absolute piece of cake shot with a rifle.
Shoot 3 Gun, enjoy yourself, learn your preferences first hand. Beyond the absolutes such as the rifle being the ideal small arms weapon, each person will have a multitude of individual personal preferences about the way they like to shoot, hold their weapon, load their ammo, move between targets, etc. Practice makes perfect. Get involved and start learning your own personal preferences through high pressure shooting.