Caliber Vocabulary

If you’re new to the shooting sports or a seasoned veteran, it can be confusing at times differentiating between the numerous calibers out there and their plentiful pseudo names. Is .308 Winchester bigger than .30-06 Springfield? Numerically speaking it’s bigger in terms of the name I provided, but in metric terms the picture becomes clearer. The .308 Winchester caliber is actually 7.62x51mm versus the .30-06 Springfield caliber being 7.62x63mm. When we say it that way, .30-06 Springfield is obviously a much larger caliber. I’ll try to explain some of the common .30 Calibers out there as well as the ranging and abundant handgun calibers you see in gun shops.

A lot of firearms jargon can leave people perplexed, bewildered, or bamboozled. Like what does A.C.P really mean when it follows the name of so many calibers? Or what the heck does F.N. mean? Well, to simplify things I conjured up a chart with some common acronyms and short hand names for calibers.

Most calibers will give credit to the original inventor like S&W for Smith & Wesson or describe the bullet diameter like .25 ACP. A lot of the American vocabulary for calibers will credit the inventors with bullet diameters making deciphering through rifle calibers pretty difficult. When it comes to the category of .30 Calibers, viewing their size visually definitely helps.

If you were to just read their names, without any previous knowledge, it would be near impossible to know which is the largest and smallest. This is where it can come in handy to know metric names for calibers. Metric designations will state the bullet diameter first followed by the length of the brass. This makes things easy because when bullet diameters overlap size can be identified without a picture or actual round.

So, if you know the names of calibers and can understand where they came from, the only thing left is to pick one if you’re shopping for a new firearm!

When it comes to .30 Caliber firearms, some people are of the mindset that you need a huge caliber or only certain calibers will do the job. If you’re hunting whitetail deer, shot placement is the most important factor in humanely and quickly downing your game, not the amount of recoil you sustained from firing your firearm. What a lot of people are forgetting is that once you pull the trigger and the bullet leaves the barrel, the same sized bullet (in varying grain weights) is coming out. I traditionally suggest customers purchase calibers that they already own, for simplicity of buying ammunition, or a caliber that is readily available in regards to finding ammo. My brother always gives the example of: If you are “in the sticks and you’re hunting,” and you stop at a tiny gas station or gun shop, would they have your ammo? If you purchase or own a .308 Win., .30-06 Sprg., or .30-30 Win. they likely would. If you have a more uncommon caliber like .300 Wby. Mag. or .300 A.A.C. Blackout, then probably not. All these calibers do have utility though, but it may not be in Minnesota hunting whitetail deer. The .300 Weatherby Magnum can kill any animal in North America; whereas, the .300 A.A.C. Blackout was adopted as a modern sporting rifle caliber which is great for hunting wild hogs in southern regions of the United States. A couple questions to ask yourself when buying a new rifle are: What calibers do I already own? Is it a fairly common caliber for ammo? And if it’s not common, do I have a specific purpose I’m willing to utilize this new firearm for? Truly knowing your rifle caliber’s size and what it would likely be used for can greatly affect your satisfaction when buying a new firearm.

When looking at handguns, you should approach them in a similar manner as rifles. Knowing caliber size, whether you’re hunting, target shooting, or using a pistol in self-defense is very important. There are a multitude of calibers to choose from nowadays from the light-recoiling, economical .22 Long Rifle to the hard-hitting .44 Remington Magnum. It can be difficult to visualize in your mind the difference between all the calibers available, so here’s a great visual!

A fairly good rule of thumb is the bigger the caliber, the more recoil and expensive it’ll be. If you’re looking to hone your shooting prowess it may be in your best interest to shoot a light recoiling and cheaper caliber. This will allow you to focus on your mechanics and the improvement of shear accuracy. If you’re looking to go hunting and inherently will not be shooting a lot of rounds, a more expensive, impactful caliber can be very beneficial. If you were ever wondering the miniscule differences between calibers the best way can be to see their bullet diameters similar to how we viewed .30 Calibers.

This brings a lot more clarity to the progression of handgun caliber sizes. When we looked at the actual bullets their heights were varying greatly; not a smooth progression like the .30 Calibers in rifles. Even with the hodge-podge of caliber heights we can see in the spreadsheet that for the most part it is a gradual progression from smallest to largest. If you’re looking for more affordable calibers in this spectrum to shoot, .22 Long Rifle would be the cheapest caliber on the market, .38 S&W SPL is traditionally your cheapest revolver caliber, and 9mm is your cheapest semi-automatic pistol caliber. If you’re in pursuit of hunting big game for a new challenge, try calibers like .44 Rem. Mag. and .45 ACP or even larger ones yet that I haven’t covered like .454 Casull or .500 S&W Magnum! These will be a lot more expensive, but are significantly more impactful when hunting. So don’t let firearm jargon bury your confidence. If you know these little differences: bullet diameter, caliber pseudo names, caliber availability, recognition of who possibly invented the caliber, and the cost of varying calibers, you’ll be ahead of the game! You’ll also likely impress all your friends knowing that your .30-06 Sprg. trumps their .300 WSM in caliber size.