Explain gun ammo language?

Question

Can anyone explain all that gun ammo talk? calibers, 30ot-6, 9mm. .45 etc...

thx!

Answer 1

calibre refers to a derivitive of kings rule. .45 = 45/100 of an inch in diameter/around. 30 aught 6 = 30/06 = .30 + 1906 (the year the army adopted it). 30/30 = .30 + 30 grains of powder. mm = millimetre, used as measure by modern armies in the rest of the world outside usa & uk. a .308 is the same as a 7.62mm.

Answer 2

Basically caliber it is the diameter of the bullet a gun fires. The designation can be metric 9mm or in fractions of an inch such a the 45 automatic which is roughly 45/100 of an inch. The issue is a bit muddled as to specifics due to the rifling grooves cut in the barrel. A 30 caliber rifle has a bore of .300" but the bullet has to be larger to fit the grooves and is normally .308". A 30-30, 30-06, 308 Winchester, 308 Norma Magnum and a 300 H&H Magnum all use .308" bullets, some are named for the bore diameter others for the bullet diameter. It is not all that logical but marketing people make up the names, not the ballistics types who develope them. Sometimes they give an approximation so two cartridges don't get confused such as the 22 caliber centerfires which have titles of 218,219,220,221,222,223, 224, 225 all use .224" bullets!

Answer 3

Hi Sonia,

H did a pretty good job of explaining things. I just want to add a few things to further muddy the waters.

Some times you see cartridge names written .25-'06 or .44-40, and the second numbers have different points of origin. For some cartridges, the such as the .25-'06, and 7mm-08 refer to the cartridge case from which the cartridge originated, for example the .25-'06 started as a .30-'06 cartridge case (the brass part) necked down to .25", and the 7mm-08 started with a .308 Winchester cartridge case necked down to 7mm.

Some of the older cartridges use what was called the American System of Nomenclature. It consisted of three numbers that was basically reloading information. The first number was the caliber, the second number was the powder charge and the third was the bullet weight. For example a .45-70-405 was a .45 caliber cartridge loaded with 70 grains of blackpowder and a 405 grain bullet. In current usage, the third number is generally dropped and cartridges are referred to by the first numbers only, such as .44-40, .38-40, or .45-70.

If you really want to understand cartridge terms, it will take some time and some study. I suggest you get a copy of Cartridges of the World, that will provide lots of info on nearly every cartridge ever used.

Doc

Answer 4

It's a secret code that we use to keep the public confused!

I'm joking, of course, but it is confusing.

It starts back a couple hundred years. Every country used their own nomenclature to describe not only the inside diameter of the barrel or the outside diameter of the projectile, but the length of the cartridge and sometimes the year the cartridge was adopted into military service and often the manufacturer or inventors name.

So for years everyone had their own standards and only in recent years has there been any attempt to standardize using the metric system, although this adoption is going slowly and we still have many older sizes that are quite common.

Even more confusing, the guys who name these sizes are often rounding up or down to a nice number they like. So a .45Colt is actually like .456 inches.

Caliber = based on inches. 1.0 Caliber = 1.0 inch

MM = Millimeter



You can find a comprehensive list of known calibers out on the web, but I'll share my favorite caliber name.

5.75 Velo Dog
(yes, I have a revolver in this size!)
5.75 Velo-Dog was a caliber originally created in France in the late 1800s as a defense for cyclists on their velocipedes (bicycles), who were likely to be set upon by large and ferocious farmers dogs on country roads. It was a small round and the point was to shoot the attacker in the face with it. Good times!

Answer 5

Sonia, the guys did a good job of answering your question but books have been written about this subject and it is hard to answer in such a small forum such as we have here. And it is also confusing even to us experts. I have been in the gun business since 1968 and even I do not know all the cartridges and what their names mean. And now the ammo companies are adding numbers to their cartridges just to make it seem like theirs is bigger and badder than the other companies. Such as 45 cal is now .454 or .460. So if you really want to study about this subject do as one of the others suggested and buy the book, Cartridges of the World. I have 4 issues of it and they still can't keep up with all the new cartridges that are invented, designed and converted or improved.
Good luck

Answer 6

Hi Sonia. Actually ammo talk is pretty confusing but here goes...

.30-odd-6 or .30-06 Springfield (same thing): A thirty caliber (first number) cartridge developed in 1906 (thus the '06) by 'Springfield.' In the .9mm the first number refers to the diameter of the bullet, nine millimeters. The second number, example .9x19mm (the 19 is the length of the bullet case; if it is .19x17mm, the 17 makes it a .380 acp rather than a full-sized .9mm). Confused already? I am, LOL!

Finally to convert from mm to American calibration multiply by 4. A .6mm becomes a .24 caliber. Note the .243 Winchester is a .6mm not to be confused with the .6mm Remington which is out of date, but actually bigger (longer case) than the .243 Winchester. If you want to convert from caliber to mm divide by four. .243 then becomes .6mm.

Hope that helped.

H

Answer 7

machine gun (b) Machinegun The term “machinegun” means any weapon which shoots, is designed to shoot, or can be readily restored to shoot, automatically more than one shot, without manual reloading, by a single function of the trigger. The term shall also include the frame or receiver of any such weapon, any part designed and intended solely and exclusively, or combination of parts designed and intended, for use in converting a weapon into a machinegun, and any combination of parts from which a machinegun can be assembled if such parts are in the possession or under the control of a person. (c) Rifle The term “rifle” means a weapon designed or redesigned, made or remade, and intended to be fired from the shoulder and designed or redesigned and made or remade to use the energy of the explosive in a fixed cartridge to fire only a single projectile through a rifled bore for each single pull of the trigger, and shall include any such weapon which may be readily restored to fire a fixed cartridge. A semi-automatic, or self-loading, firearm is a weapon that performs all steps necessary to prepare the weapon to fire again after firing—assuming cartridges remain in the weapon's feed device or magazine. Typically, this includes extracting and ejecting the spent cartridge case from the weapon's firing chamber, re-cocking the firing mechanism, and loading a new cartridge into the firing chamber. Although automatic weapons and selective fire firearms do the same tasks, semi-automatic firearms do not automatically fire an additional round until the trigger is released and re-pressed by the person firing the weapon. The first two are from the national firearms act. The last from wiki. The term semi automatic machine gun is an oxymoron, as semi automatic and machine gun are mutualy exclusive terms. Since this semiautomatic machine gun doesn't exist it would be impossible to hunt with, or fire one at all.

Answer 8

Caliber refers to the approximate diameter of the bullet in hundredths and thousandths of inches or in millimeters. 30-06 is an exception in that the bullet diameter is 308 thousandths and it was adopted by the armed forces as the standard battle rifle in 1906.

Answer 9

they're bullet sizes, *****