Why choose a pistol caliber carbine instead of a pistol for self defence in the home

As a firearms instructor who is active in the community, I often get asked what the best firearm is for protecting one's family and home from armed aggressors. As I live in the United States, we have many options. In this post I'm going to illustrate some reasons why a pistol caliber carbine offers some advantages over a handgun.

First, what is a pistol caliber carbine? It's a short rifle (carbine) that is chambered in (fires) a cartridge that is traditionally used in handguns. The most common ones in the US fire 9mm, 40 S&W, 45 ACP, 357 Magnum, 44 Magnum and 45 Colt. They offer 4 notable advantage over pistols chambered in the same cartridge. Are they the best choice for defending one's home? Perhaps not. Are handguns much handier for carrying day to day? Certainly! But in one's home the small form factor of a handgun may be a detriment for reasons I'll explain below.
The AR-15 is a very popular carbine in the US, this is one chambered in 9mm

Reason 1 - They are more powerful than handguns
A rifle firing 9mm is more powerful than a pistol firing 9mm. How can this be since it's the same cartridge? Because a longer barrel allows for more acceleration of the bullet than a shorter barrel. The muzzle flash you see when a handgun is fired is powder that isn't burned inside the barrel and is instead flashing outside the barrel. This is wasted energy. In a longer barrel that energy is used to push the bullet faster. Students of physics know that energy is related to velocity. In fact, velocity is squared in the equation, so increasing velocity has a greater effect on energy than mass. In a cartridge like 9mm (aka 9mm Luger, 9mm Parabellum, 9x19) you get a 35% increase in energy in a 16" carbine barrel over a 4" pistol barrel. That's pretty significant. That extra energy means the bullet has a flatter trajectory and carries more energy to the target.

For more information on the effect of barrel length on different cartridges, I recommend the website Ballistics By the Inch.

Reason 2 - Rifles are easier to shoot well than handguns
This statement may be controversial, but I stand by making it. After working with scores of students, as well as many more new and experienced shooters over the last 20 years, people can learn to shoot moderately well with rifles in far less time than with handguns. I'm speaking of basic proficiency here, each take hundreds of hours to truly master. For the occasional user, a rifle is easier to be, and stay, proficient with. Why is that? A few reasons.

First, a rifle has a longer sight radius than a handgun. Sight radius is the distance between the front and rear sight- the longer it is the easier it is to line up the sights in a precise manner. This can lead to more accurate shots and quicker sight alignment. Accuracy is key in a home defense situation! Any shots that miss the target can go on to strike other objects or people that are not intended. That makes the shooter a dangerous and illegal actor.

Carbines are easier to hold steady than handguns. This is due to how many points of contact you have with them. On a handgun, you have both hands sharing a single point of contact, and any shake or wobble is quite evident. With a rifle you have each hand grasping a different part of the gun and you have the gun pressed against your shoulder and you have your cheek pressed against the stock as well. That's 4 different points of contact. If you add a sling, you can stabilize a rifle with even greater ease. Yes, it's challenging to hold either completely steady, but it's easier to keep a carbine on target than a handgun.

The same cartridge fired in a rifle has less muzzle flash and makes less noise than in a handgun. I've found that many flinches are caused by muzzle blast (the combination of flash and sound) and carbines have less. This is because all the powder burns inside the barrel and it's helped by the muzzle being further from your face. They have less flash, are quieter and that blast happens further from your face than a handgun. That helps prevent developing habitual flinches. It also is less likely to blind the shooter at night. A bright flash ruins human's ability to see well in the dark.

And lastly, we have reason 3, a topic important enough I granted it it's own section.

Reason 3 - A rifle has less felt recoil than a handgun
This is one of the most important reasons a pistol caliber carbine is a better tool than a handgun is perceived recoil. I use the descriptors of "perceived" and "felt" because there is more to recoil than simple math. Of course, even with simple math the carbine wins out. The energy created by the cartridge firing is a constant, and carbines weigh more than handguns, often 3 or 4 times as much. Since recoil is the energy of the cartridge acting to accelerate the firearm, a heavier firearm resists that motion more than a lighter firearm. Heavier guns kick less. Lower weight is an advantage for something you carry with you all day, but it is a disadvantage for recoil.

As well we discussed earlier how rifles have more points of contact than handguns. A handgun transmits the recoil entirely into the hand that is grasping it. Powerful handguns push hard against the palm and can flip (rotational energy) in the hand. A rifle spreads that recoil out across the points of contact. So not only does a carbine recoil less, that recoil energy is spread to more parts of the body. A carbine is more of a push versus the hard slap of a pistol.

As well, muzzle blast contributes to felt recoil. We already discussed how a rifle has less muzzle blast than a pistol that fires the same cartridge. Why does recoil matter? Less recoil means it's easier to stay on target. Less recoil means faster second, third and future shots. Less recoil contributes to better practical accuracy. Less recoil means keeping your eye on the attacker rather than focusing on controlling recoil.

The Rossi Model 92 is available in several pistol caliber chamberings and is a time proven design

Reason 4 - Practical matters
There are several practical matters that give carbines the benefit as well. The first is that handguns aren't legal to own by citizens in some areas, they are restricted to police and military use. As well, in some cultures handguns are viewed as the tool of the bandit and looked down upon in social groups, even when they are legal. If you defend yourself, your home or your family with a firearm you will likely face charges in court. The opinion of your peers matter.

Pistol caliber carbines are often more affordable than handguns as well. Since they use the same ammunition as handguns, they don't cost any more to practice with. A person with a $300 gun and $200 of ammunition to practice with is going to be a more effective shooter than a person with a $500 gun and no budget left for practice.

Many pistol caliber carbines have greater capacity than handguns. A 38 caliber revolver commonly holds 5 or 6, or sometimes even 7 or 8. A lever action carbine that shoots 38 special will commonly hold 8 or 10 shots. A 9mm Glock 17 holds 17 rounds, where a 9mm Colt AR-15 holds 32. Having extra capacity is always of benefit, especially if facing multiple attackers.!

Lastly, a rifle, with it's multiple points of contact, is easier to hold firmly and keep control of in a violent confrontation. A handgun is more easily knocked from a grasp. Losing one's firearm to an attacker is the worst possible outcome of a defense scenario.

Final thoughts
Please note at no point did I say a pistol caliber carbine is the best weapon to defend one's home and family. I'm only making the case that it's a better choice than a handgun for the above listed specific reasons. What's the best weapon to protect your home? Probably a tank. And 50 armed soldiers. However, that's an infeasible choice for all but the wealthiest or most powerful people. The rest of us must make compromises.

No one wants to imagine a moment in the future where they are fighting for the safety of their self or family, but as responsible people we often must. It's why we keep insurance, even though we hope we won't need it. It's why we keep a fire extinguisher in our home, even though we don't plan on having an out of control fire. We take steps today so as to best survive a possible tragedy in the future. If you are a person who is considering acquiring a firearm for defensive purposes, I hope my thoughts on the topic have been helpful.

I hope your future days are well and such a tool would never need to be used!