Internet Caliber Wars

Everybody loves a good caliber war and everybody is an expert on ballistics. This is why everybody knows that their pet cartridge is the absolute best and everybody should immediately rush to adopt it. But what makes a cartridge better? Why is a rifle chambered in 6.8x51mm superior to a rifle chambered in 5.56x45mm? Why will carrying a handgun chambered in 9mm get you killed on the streets?

I'm going to start with the spoiler. The answer to the above questions in order are: it depends, it's not necessarily, and it won't. There are no magic wundercartridges. What makes one cartridge better than another depends on a lot of factors. Let's consider the 6.8x51mm versus the 5.56x45mm debate for a moment. There's no denying that the 6.8x51mm delivers more kinetic energy to a target over a longer range. The 6.8x51mm also shows superior performance against body armor. Obviously it must be better, right? Not necessarily. The 6.8x51mm is also heavier, produces significantly more recoil, is far more expensive, only works in one gun (maybe there are one or two more as of this writing), and is damn near impossible to find for sale.

I have a tough time imaging a scenario where I'd have to hit a target wearing body armor at 300 m. In all likelihood, I'll never need to use a firearm in self-defense. If I do, it's unlikely the attacker will be wearing body armor. It's even more unlikely that the engagement range will be more than a few feet. 5.56x45mm, 9mm, or 12 gauge will all be effective.

Ballistics and kinetic energy aren't the only criteria when comparing cartridges. Logistics are also important. A cartridge you can afford to shoot regularly is going to be more effective than a cartridge you can't. It doesn't matter how much kinetic energy a cartridge can deliver to a target if you can't hit the target with it. You can't miss fast enough to win. Other consideration is the firearm. Continuing with the 6.8x51mm versus 5.56x45mm comparison, consider the weight of the M7. The gun weighs about 8.3 pounds. It's also one of the only guns chambered in 6.8x51mm. There is a seemingly limitless number of guns chambered in 5.56x45mm. If you use 6.8x51mm, you better fit the M7. If you use 5.56x45mm, you can find a rifle that will fit you.

I've focused primarily on rifles but the same is true for handguns too. The ballistic difference between the .45 Auto and 9mm is far less than the difference between the 6.8x51mm and 5.56x45mm, but the .45 Auto looks slightly more impressive on paper. But 9mm gives you several advantages. The 9mm is a physically smaller cartridge so you can fit more of them into the same size gun. Finding cheap 9mm ammo is easier than finding cheap .45 Auto ammo so you can afford to practice with it more. There are more guns chambered in 9mm too, which means it's far easier to find a gun that fits you.

The scenario also plays into decided which cartridge is better. If the scenario requires hitting a person 300 m away, both the 6.8x51mm and 5.56x45mm will be better than a 12 gauge by the merit that they can reach the target. What about at close range though? For example, a home defense scenario. Unless you live in a mansion (in which case I doubt you're reading my blog), the longest shot you're likely to take inside of a home is a few yards. The dynamic between either the 6.8x51mm or 5.56x45mm and the 12 gauge changes dramatically at close range. A 12 gauge shotgun with proper ammunition can deliver a devastating amount of hurt on a target standing a few yards away. It will deliver far more hurt in a single shot than most rifles at that range. Internet commandos are often quick to point out that a shotgun can only hold a few rounds and is slow to reload. They then declare the rifle better because it can hold more rounds and is faster to reload. But how many rounds are you likely to need in a home defense situation? I feel safe saying it'll likely be between zero and three and largely depends on the number of people breaking in.

In summary, there is no best cartridge. Every cartridge in the world has trade-offs. If this weren't the case, new cartridges wouldn't be developed. Trying to argue that one cartridge is objective better than another is pointless because better is largely subjective and scenario based.