I am a proponent of minimizing your self-defense firearms arsenal. I don’t mean that you should only have a few guns, but I do believe the amount of defensive firearms you rely on should be kept to a minimum concerning different platforms. I am absolutely opposed to the “carry rotation” with defensive handguns. Carrying a 1911 on Monday, a Berretta 92 on Tuesday, a Glock on Wednesday etc… makes no damn sense at all. Some guys do this and I absolutely can’t figure it out. I am also opposed to juggling too many long gun options because the same issue of familiarization applies.
Humans are surprisingly limited in their ability to become truly proficient with a large variety of tools that require different manipulations. Therefore, the more time you spend with a particular weapon platform the better you will perform with it under stress. You don’t need to stick with only a couple of guns your whole life, it is inevitable that shooters change guns, but you should do so according to your actual needs and you should spend significant durations of time with a particular platform. Certainly don’t rotate guns on a daily basis.
Changing guns on a seasonal basis, perhaps due to concealment issues due to hot or cold weather, makes more sense and longer time durations facilitates more adequate training time on a platform. Or, if you decide you like a particular handgun platform better than the one you currently use, then make the switch. But avoid the different gun every day routine. Regardless of what guns you settle on for any duration of time, you may find that you need at least three defensive firearms to have all your needs covered.
When discussing a trio of firearms many may presume I refer to a shotgun/rifle/handgun lineup. Not so. My suggested trio of defensive weapons is as follows:
First priority: Full-size or compact handgun. This is going to be a service pistol or the compact version thereof. A capable fighting handgun that hopefully you carry most of the time.
Second Priority: A small and concealable handgun. Not many people have the luxury of being able to conceal their full-size gun all the time. You may need a very concealable weapon for certain occasions. This is where the single-stack 9mm autos, small-frame revolvers, or even the uber-tiny pocket autos come into play. A small gun is great if the only alternative is no gun. If you adopt a small gun that is in the same family as your primary handgun that even further maximizes your cross-training familiarity, but this may not work for you.
Third Priority: A defensive long gun. Shotgun or rifle is a personal choice based on your needs and circumstances. The bottom line is either outclasses a handgun for power and performance, so having a dedicated defensive long gun available in the home is wise.
My suggestion is to choose your favorite weapon in each of these categories and prioritize your training time on these. Maybe you are a 1911, J-Frame, and Remington 870 guy. Awesome. Maybe you are a Sig p320, Ruger LCP, and AR15 guy. Great. It does not really matter, but what does matter is that you prioritize these guns and maximize your familiarization with them.
I think prioritizing practice with either a rifle or a shotgun will serve most people better than spreading training time and resources between the two and being less competent with either. If you are a high volume shooter that does enough training on each platform then no problem, but I think for most training time is limited and better spent on one or the other. These three weapon categories will cover all of your self-defense needs and limiting your focus to just three platforms will maximize your proficiency with them.