This is probably a really stupid question, BUT...

[Steelharp]

There are no stupid questions, just stupid people, right? I qualify. My son asked me where do the numbers for the different calibers come from, and I didn't know what to say! What is the measuring stick for 45, 44, 357, 22, etc.?

Mikey

[TCPilot]

Hey Steelharp,

The only stupid question is the one you don't ask...

Most calibers come from the diameter of the bullet; i.e. a .45 is 45/100 inch in diameter. This gets a little hazy, as a .357 Magnum handgun can also fire .38 Special. But, for the most part, the caliber is the diameter. Same goes for mm measurements; 5.56mm, 7.62mm are .223 and .308 respectively.

Shotguns, on the other hand, use a different measurement. Gauge is the measurement of how many equal-sized bore-diameter lead balls it takes to make one pound. For instance, a 12-gauge shotgun, if you were to make 12 bore-sized lead balls, would equal one pound. 16 and 20 gauge are obviously smaller (still one pound, but more balls!).

Things really get confusing when you talk about .30-06, .308, .30-30, .303, .300 winmag, etc. All are .30-cal, but the cases vary widely in length, breadth, and powder load.

HTH,

/TCP

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Measure Twice....Cut Once

[Gary W Trott]

Dear Steelharp,

I'd like to continue along a little with TCPilot's excellent answer by explaining some of the designations:

.30'06 = thirty caliber cartidge adopted by the military in 1906.

.30-30 = thirty caliber cartridge with 30 grains of powder.

the .30'06 Springfield, .30-30 Winchester, and .308 Winchester all use the same diameter bullet (I'm not sure offhand if the .300 Winchester Magnum does or not)

Other two part designations you might come across will often denote the caliber and the original casing which was necked down (had the diameter decreased) to make the new cartridge. These will have the two numbers separated by a slash. The bullet diameter will be the first number, and the original cartridge will be the second. For example: .25/06 is a twenty five caliber cartridge made from the .30'06 case. The Europeans do this in reverse with the original case first and the necked down caliber second.

And with shotguns the .410 is a caliber NOT a gauge.

If you haven't already buy your son the 2002 copy of "Gun Digest" or "Shooter's Bible" for Christmas. They're jam packed with neat information and guns. I've always loved going through them but never so much as I did as a child. Happy holidays. Stay safe, Gary

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"I knew a man that I did not care for. And then one day this man payed me a call. We sat and talked about things on our mind. Now this man he is a friend of mine" Friend and Lover "Reach Out in the Darkness"

[sfcbhunt]

With most handgun cartridges, the "name" is related to the diameter of the bullet. This is true for 22, 25, 32, 9mm, 10mm, 40, 41, and 45.

(22 = 0.224" diameter bullet, 45 = 0.451-0.452 diameter bullet, etc.)

With some handgun cartridges, the outside diameter of the cartrige case is where the name comes from, 380,38 and 44 being the most prevalent. With those, the name approximates the case diameter, while the bullet diameter is smaller. (The 44 magnum case is somewhat larger than 0.44", while the bullet is around 0.430" in diameter.)

There's probably a fascinating history about how all this happened, but I've not come across it yet. The key thing with all ammunition is that what is stamped on the box and the heads of the cases MUST match what is stamped on the gun or stated in the owner's manual.

[feedramp]

From the Gunnery Network's Gun Glossary:

CALIBER: The nominal diameter of a projectile of a rifled firearm or the diameter between lands in a rifled barrel. In this country, usually expressed in hundreds of an inch; in Great Britain in thousandths; in Europe and elsewhere in millimeters. In reloading the diameter of the bullet in inches or millimeters bullet weight-measured in grains (7000 gr/lb) or grams. Used to identify appropriate ammunition for a firearm. Abbreviated Cal. Caliber 2: Ammunition is measured in terms of "caliber". As a loose rule for beginners, the larger the decimal fraction, the "higher" the caliber and the more powerful the ammunition (i.e. a .22 caliber is smaller and weaker than a .45 caliber). To put caliber in a general context, a .22 is the smallest common caliber. Calibers ranging from .22 to .32 caliber are considered "light" and are best suited for target shooting. Calibers from .38 to .45 (which includes the common 9mm and .357 magnum) are commonly selected by law enforcement agencies as "defensive calibers". This means that they are powerful enough to serve with reasonable reliability in a defensive role. "Heavy" calibers such as .44magnum, .454 Casuals and .50 cal produce incredible amounts of energy and may require special care with respect to a safe shooting area. Be wary - courts may place a greater liability burden on the defensive use of heavy caliber firearms, or view the decision to employ such force as excessive. (There is considerable debate as to whether it is safer in a defensive effort to fire one powerful bullet capable of stopping a threat definitively and immediately, or having to fire multiple "less powerful" bullets. You should keep this issue in mind as you explore any analysis of personal defense.) Shotgun Ammunition is measured in GAUGE.

GAUGE: The bore size of a shotgun. In this case bore refers to the inner diameter of the barrel. Gauge is determined by counting the number of round lead balls of bore diameter that equals one pound or 16 ounces. No not kidding. It is an old and antiquated method of measure that most people do not know about. Thus 12-gauge or 12 bore means that 12 pure lead balls of such a diameter will weigh one pound. The sole exception to this is the .410 shotgun, which has a diameter of .41 inches (i.e., .41 caliber). Note: Sometimes GAUGE is spelled GAGE.

GAUGE, SHOTGUN: The unit of measure of the bore diameter of a shotgun. The gauge is the number of lead balls, of the diameter of the gun bore, that make a pound. While most ammunition is described in terms of caliber, shotgun ammunition (called a Shell or Shotgun Shell) is described in terms of gauge, and the direction of the scale is reversed. So the lower the gauge, the bigger the bore diameter and the more powerful the shell. A 12-gauge shell is larger and more powerful than a 20-gauge shell.

http://www.gunnery.net/glossary/index.html


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[Jim V]

The reason, or one reason, bullets of a .357 diameter are called .38's came from the old "heeled" bullets where the bullet was actual case diameter and a smaller "heel" was crimped in the case. If you look at the .22 rimfire family and exclude the .22 Mag, you will see the bullet is the same size as the case, heeled bullets at work.

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[TCPilot]

Hey JimV,

I posted here to answer this, and learned something (duh!)! Thanks for the hint on .357 v.s .38, and heeled bullets. I always wanted to know that!

Gary, thanks for the continuation...and the reminder of 410 shotgun...forgot that one .

/TCP

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Measure Twice....Cut Once

[Orion]

okay, just to start something, How come .45's are so much better then 9mm?

(before you answer let me get outta the way)

[TrophyShop]

Here's some confusing ones:

.218 Bee

.219 Zipper

.220 Swift

.221 Fireball

.222 Remington

.223 Remington

.224 Winchester

.225 Weatherby

Bunch of different bullets, Huh? Nope, there all .223

(edited because I can't type)

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"No dumb bastard ever won a war by dying for his country. He won it by making some OTHER dumb bastard die for HIS country!"
General George S. Patton Jr.

[This message has been edited by TrophyShop (edited 11-28-2001).]

[Grey Taylor]

My ex-wife used to ask me why certain cartridges were named whatever they were named. Usually I could make sense of it for her but was never able to give her a clear cut rule of thumb that covered all (or even most) cartridges. When she asked me about a wildcat it got really interesting and she'd always end up throwing her hands up in frustration.

[Gun Nut]

Originally posted by Orion:
okay, just to start something, How come .45's are so much better then 9mm?

(before you answer let me get outta the way)

You should start a different thread here. It would be off topic to reply here. That being said, I will add that saying .45 is "so much better than 9mm" is a fairly subjective statement.

Is a .45 so much better than a 9mm in a 17 oz gun? I don't think so. 9mm has its place. I would use it in applications which I think fits it best, a la in a CCW package in which I needed a lighter and smaller gun than I could get, and comfortably shoot in a .45.

Why do I like the .45 over the 9mm? 230 grains vs. 115 grains. Twice the weight and makes a bigger hole.

[dsk]

Without starting another .45 vs. 9mm war here, I'll say that a .45 and a 9mm are both at their best when in a suitable platform. In other words, when the .45 is in a full-size, steel gun that takes advantage of its terminal performance out of 5" barrels it can't be beat. Yet in a small, compact carry gun the 9mm is great because you can pack a lot of power in a tiny package.

Take a big fat 10-round 9mm you can't conceal, or a tiny .45 with no grip frame on it to hold onto and you have something that is neither fish nor fowl.

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D. Kamm
USGI M1911/M1911A1 Pistols Website
http://usgi1911.tripod.com

[elsworth]

A 12 gauge is ~ 72 caliber
That's what a good .45 caliber hollow point can expand to, think about it

Don't know what a 20ga. is. Wish I did, though.

[shooting fan]

OK, what about the 22-250 and the 45-70?? How do those fit into this mess??

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Just because you're paranoid doesn't mean they're NOT out to get you.

Don't be afraid of the Truth

[Roger D]

The 45-70 is an easy one (i.e. I know it!!), .45 caliber and originally, the case contained +/- 70 grains of black powder (sometimes expressed as 45-70-500. The 500 was the weight of the bullet originally loaded in the cartridge).

Cases back in the 1870's were slightly belled and somewhat thinner than todays cases for the same cartridge and may hold a few grains more powder than do modern brass. For example, I can get "only" 64 grns. max of FFg (Goex) into a Wincherster 45-70 case under a properly seated 405 gr bullet.

Other familiar older cartidge designations include (caliber-powder charge): 25-20, 38-40, 32-20, 38-55, 40-65, 40-70, 44-40, 44-77, 50-70 ... etc. etc. etc. (literally "scads" of them).

As for the 22-250 ... thats a tough one!!!(i.e. I don't know it). Any help???

Regards,

Roger D

[This message has been edited by Roger D (edited 12-04-2001).]

[This message has been edited by Roger D (edited 12-04-2001).]

[batwing]

Hi DSK,

Take a look at the new Springfield Micro Compact. It might give you a different opinion of a .45 in a small compact carry gun. I just bought one this past weekend and just fired it for the first time this evening. I can get all my fingers on the grip and the recoil is no greater than my much heavier TRP (probably due to the design of the recoil spring). It's going to be my carry gun replacing the Glock 23.

[Wayward]

22-250, 22 caliber bullet with a 250 Savage case.

[msmith]

A 20 guage is about .62 cal.