I am sure this has been asked before caliber sizes

[markofkane]

I was wondering. Why so many caliber sizes? Why have a 9mm versus a .357 magnum? Is it the price of ammo, or what? I know .22 cal (I think) is the cheapest ammo. That is good for those who want to target practice at maybe the lowest cost. Why not just go for the max size if you want to use it for defense? I know these questions sound dumb, but I want to know.

 

[spacecoast]

Not a dumb question, it's a good question.

Semi-auto (9mm) and revolver (.357 mag) cartridges operate in different types of handguns (with a few exceptions), so they have to be considered separately (hence doubling the number to consider right away).

In general, a given cartridge covers a certain range of power/bullet weights and doesn't overlap completely with "adjacent" cartridges in the same family, although there is usually some overlap. Often certain cartridges are "improved" for additional power or flexibility and released as a new cartridge.

For example, the .38 special dates from the black powder days (pre-1900). In 1935 it was lengthened and released as the .357 magnum, which is capable of much higher velocities. The length increase prevents the .357 mag from being chambered in .38 special guns which couldn't handle the increased pressure.

In general, the larger the diameter (caliber) of the cartridge, the heavier the bullet it is capable of firing. Heavy bullets (in handguns) are better for stopping larger animals, but the larger cartridges (generally) require larger guns. With a wide variety of applications, all the way from super-small and light pocket carry guns to heavy long-barreled hunting revolvers capable of bringing down large game, the proliferation of the cartridges becomes plausible (but still confusing until you've stared at it a while).

 

[TXHootus]

Indeed it is a good question.

Firearms cartridges come in the huge variety they do because in each case a person decided they wanted a cartridge like that, probably for certain performance reasons. Given that firearms cartridges have four basic components -- projectile (bullet), cartridge case, powder and primer -- and that there are miriad choices for projectile weight and caliber, powder burn rate and charge density, and case volume/strength, the number of possibilities is staggering.

Most of the cartridges out there have been developed to meet a specific requirement that the developer had in mind. There are many trade-offs in size, power, weight, etc... that play into the requirements the developer seeks to fulfill.

Taking your question about defense cartridges, for example, there are reasons some folks don't choose the "max size". Max size might mean 12 ga. shotshell, .50 BMG, or .50 AE among readily available cartridges. No reasonable conceal-carry arms are chambered in any of these, so if you need an arm to conceal these cartridges would be out of the running. Similarly, if you need a cartridge to stop a man, .50 BMG or .50 AE might introduce severe overpenetration into the equation and since you are responsible for each bullet fired this is clearly undesirable. Also, the simple size of the cartridge may mandate limited magazine size for handguns -- I don't think very many humans could wrap their hands around a hi-capacity double-stack .50AE magazine which is why no one makes them.

 

[briandg]

A simple explanation is that every bore diameter from .22 rimfire all the way up to the .458 magnum is a needed step in firearms efficiency. taking rifle cartridges for example, a 224 caliber centerfire is usually fast and flat shooting. A .250 caliber is effective for medium to large game. a 30 caliber is effective for medium to large game, and a .35 caliber will handle almost any animal in america. A .45 caliber rifle with heavy bullets and high velocities will drop anything, from the elephant down to a raccoon.

Among these bore sizes, you have various cartridges intended for different purposes; some are used at slow to moderate speeds, and others, sometimes called magnums, are pushed to high speed and high energy levels. Each cartridge has a range of bullet weights that can be used, depending on what the job at hand is.

Regarding why there are so many different bore/cartridge sizes, all over the world, for over a hundred years, people have been creating specialized guns and ammunition, and for example, european makers used the metric system, where we used fractions of inches. We chose .25 and .30, for example, and the euros used 7mm and 8mm.

There are just so darned many niches to fill, and there are people willing to create a new cartridge to fill every niche. That is why there are so many cartridges.

 

[sgms]

Very good info. in the posts so far. And you are correct, the .22 rimfire is the lest expensive of the easy to find ammunition. And a great caliber for plinking, target shooting, or match (bullseye type), It has a place in the self protection arena also but is a very poor one to use for this unless there is an over riding need, such as hands to weak to handle recoil of anything larger. You question about going to the max size for defense is also a good idea. However you must temper the 'max size' with how is the gun going to be used? You want the largest caliber that you can 1/ handle well(most often not to much recoil) , 2/is an appropriate size for it's function(like for home defense a 12 gage shot gun is outstanding but in a CCW application it is an absurd selection),3/is in a platform you are can use effectively(revolver or semi-auto), and 4/ has an ammunition price point where you can afford to train/practice enough to use it well.

 

[(*_*)]

You could make a reasonable argument that there are much fewer calibers in wide spread use then there are total calibers produced. I am trying to consolidate my calibers and will end up with all 9mm handguns at some point in the future. Why? No good reason I just figure for defense a handgun is at such a huge disadvantage to a rifle anyway. My rifle cartridges seem to be moving toward fast and flat shooting with the exception that I think I want a 45-70 lever gun because I like the idea history that goes with it. From a hunting stand point you could make a pretty good argument for just .44 magnum if using handguns. Er and 22

 

[C0untZer0]

The .44 magnum is a pretty versatile round, in a handgun it's a pretty potent SD stopper, in a carbine it will take big game, elk, wild hogs, big horn - whatever, as well as stopping grizzlies.

I do think the 9mm is the most versatile.

Of the major calibers, the 9mm is the caliber that gun makers have been able to design the smallest non-derringer package for and have that pistol be a reliably functioning pistol (Rohrbaugh R9). In carbines shooting +P or +P+ ammo, it approaches .357 velocities or what you'd get with 357s out of short-barreled revolvers at least.

I have read a few posts about people hunting deer with it. Usually when I hear about people hunting game with an odd load - they have a jones for that particular caliber or something and they're trying to prove what a great round it is.

I wouldn't trust my nines to fend off grizzlies, or cleanly put down a deer, but a nine can fit almost every other handgun role, from pocket pistol, BUG to duty sidearm.

 

[Jo6pak]

There are so many different calibers because cartridge designers had the spectaculor forsight to forsee the invention of a thing called the internet. And on this internet would be forums, and some of these forums would be firearm related. And these firearm forums would need endless minute details to discuss and argue about. So they invented a multitude of calibers, cartridges, and loading to keep us busy long enough for them to design even more calibers, cartridges and loadings to keep us moreso occuppied.

And tho the cartridge creators looked down upon the multitudes of cartridges and smiled