There’s a common thought among pro–2A people that you can never have too many guns. There’s a certain logic to it, but if you’re talking about how many you can carry and use at any one time, then, weight and the ability to safely retain those firearms becomes a challenge.
For this reason, some argue that it’s not advisable to carry a second firearm as you’ll just be weighted down, limiting movement to an extent. Some may even argue that you should just carry much more ammunition in the way of additional loaded magazines on your person instead of carrying a second firearm.
But there is an argument to be made for carrying a backup gun on your person as part of your everyday carry “kit.” In fact, Massad Ayoob says that there are at least five different situations which can come up, any of which can justify having that backup gun (hat tip to here for the lead).
Ayoob says that the first situation is an accessibility situation. Ayoob writes,
Your backup may be easier to reach than your primary. Case One took place in South Carolina. In fact, the involved officer told me he had decided to get an ankle gun after reading one of my articles in Combat Handguns. The day came when a man approached his parked unit and opened fire from the driver’s side, wounding him. Unable to draw from his Level III security holster while seated, the officer drew his backup Colt Agent .38 from his ankle holster and emptied it into the would-be cop-killer, dropping the man before he could chamber a second round. Though scarred, the wounded officer survived and returned to duty.
Thankfully, that officer had that backup gun. The other four situations that Ayoob mentions in which a backup gun can be helpful are as follows (in his own words):
“You may be separated from your primary.”
“Your primary gun may run dry, and your fastest ‘reload’ may be another gun.”
“You may be fighting with your would-be murderer for your primary handgun.”
“You may be disarmed of your primary weapon at gunpoint.”
Because of all five of these types of situations, you can argue that it is more than reasonable and rational to have a backup gun on your person at all times. As you go through the world, practicing your situational awareness, it could also be useful to consider what you would do if you were deprived of your primary carry firearm. Then, it may be worth considering what backup gun that you want to carry and how you want to carry it.