Guns and Ammo Nomenclature Questions

[Orlong]

Why are some guns labeled by caliber, and some are labeled by millimeter (what is being measured in mm anyway, is it the diameter of the casing? the bullet?)? For instance 40 cal and 9 mm. Why isnt there some sort of standard so you can tell how powerful the gun youre buying is? It would be much easier if everything was labelled as caliber so you know the bigger the caliber, the more powerful it is, or is that not always the case? Some guns arent even labelled by either such as the M16. That doesnt tell me anything about the power or deadlyness of it. And what does the number represent on a gun that is neither caliber or mm? (like a 30.06 or 287)

[Deleted]

Why are some guns labeled by caliber, and some are labeled by millimeter? For instance 40 cal and 9 mm. Why isnt there some sort of standard so you can tell how powerful the gun youre buying is? It would be much easier if everything was labelled as caliber so you know the bigger the caliber, the more powerful it is, or is that not always the case? Some guns arent even labelled by either such as the M16. That doesnt tell me anything about the power or deadlyness of it.

I'm sure there will be a tidal wave of gun enthusiasts coming to tell you all about it, but I can't imagine it's much different to anything else. We have several different ways to label temperature or distance or weight or whatever. Historically things were done one way, then other people decided that they should make a new system, some people adopted it, others prefer the old system.

For example, it's pretty easy to envisage a situation where, lets say once upon a time there wasn't really any kind of standard for gun labelling, but a bunch of people used caliber (whatever that is. I don't know about guns) then some company comes along and is like "We don't wanna display caliber so prominently because that's not what we are about so we'll just stick to using model names (like m-16 or whatever I suppose?) and then some other guy comes along and is like "There are too many different ways to label guns, we need a uniform system that everyone can work to, we'll label everything with millimters so everyone knows what it's chambered for" but not everyone wanted to adopt that system so now there are three different systems for labelling.

[Deleted]

9mm was invented in Europe where we mostly use the metric system, the military prefer the metric system too hence the 5.56 rounds as opposed to the civilian equivalent which is the .223.

As for deadliness of the round, size means jack shit. 9mm (a pistol round) is far larger than a 5.56 (M16 Rifle round) but 9mm has shorter range and less accuracy.

[Deleted]

A 9mm bullet is 9mm metric caliber. Caliber just means the diameter of the bullet or the inside of the barrel. There's no such thing as 40 cal. What you're referring to, is most likely .40 caliber, which is 0.4 inches in the inch caliber.

The caliber of the weapon won't tell you it's power.

[Deleted]

Also of interest:



Image from XKCD

[Kalis]

A 9mm bullet is 9mm metric caliber. Caliber just means the diameter of the bullet or the inside of the barrel. There's no such thing as 40 cal. What you're referring to, is most likely .40 caliber, which is 0.4 inches in the inch caliber.

The caliber of the weapon won't tell you it's power.

If it was 40 caliber, it would be a bloody big gun.

I'm guessing this is about 18 in diameter, so 40 caliber would be more than twice the diameter...

[Mormolyce]

What DOES determine the lethality/stopping power/whatever of a round? Grains of gunpowder?

[Afrospinach]

What DOES determine the lethality/stopping power/whatever of a round? Grains of gunpowder?

http://en.wikipedia.org/wiki/Terminal_ballistics

If you were to dumb it down it is a combination of how much energy a projectile has in the first place coupled with how much it is going to expend in the target, by expansion or fragmentation.

[Deleted]

What DOES determine the lethality/stopping power/whatever of a round? Grains of gunpowder?

Depends on so many factors, but the one thing most people agree on is the ability to shred as much flesh as possible. Hollow points are specifically designed for this....



Because they spread they tend to lose accuracy, hence the reason the Military rarely uses them but just fine for pistols.

[Kalis]

Depends on so many factors, but the one thing most people agree on is the ability to shred as much flesh as possible. Hollow points are specifically designed for this....



Because they spread they tend to lose accuracy, hence the reason the Military rarely uses them but just fine for pistols.

I thought the military didn't use them due to the Geneva Convention, or some such agreement.

[Orlong]

9mm was invented in Europe where we mostly use the metric system, the military prefer the metric system too hence the 5.56 rounds as opposed to the civilian equivalent which is the .223.

As for deadliness of the round, size means jack shit. 9mm (a pistol round) is far larger than a 5.56 (M16 Rifle round) but 9mm has shorter range and less accuracy.

What does the .223 mean then? Is that 223 millimeters? or inches? or some other measurement

[Kalis]

What does the .223 mean then? Is that 223 millimeters? or inches? or some other measurement

Inches. I think the general rule is inches if it's point something, and mm if it states it.

You can tell by the numbers though, e.g. think how large a 223 mm diameter shell would be (that's almost a inch in old money).

[Deleted]

What does the .223 mean then? Is that 223 millimeters? or inches? or some other measurement

Inches, it is .223 of an inch wide. You guys really need to adopt the metric system, it is much easier.

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I thought the military didn't use them due to the Geneva Convention, or some such agreement.

Kind of a screwed up rule when you allow Civilians to own and use them but not the Military.

[Kalis]

Kind of a screwed up rule when you allow Civilians to own and use them but not the Military.

It's my understanding that they are allowed for non-military use due to lowering the risk of collateral damage, but banned in the military due to how they react on impact, as soldiers shouldn't have to suffer unduly...but that does somewhat infer "fuck civilians".

[Deleted]

Kind of a screwed up rule when you allow Civilians to own and use them but not the Military.

Again, I don't know anything about guns and stuff, just repeating what a friend who likes guns has said to me, but like.. Isn't that the thing that like... JHP is less likely to go through someone than FMJ, so if you have to defend yourself or whatever it is that Americans do, you are less likely to hit someone behind the person that you are defending yourself against. That, and keeping civilians using JHP instead of FMJ means they are less likely to be able to hurt a police officer wearing a vest. Meanwhile, isn't the army more about maiming a certain number of people and killing a certain number, so that like, the healthy people have to tend to the injured, so a more lethal round isn't always better, and in a military setting you are more likely to have to shoot someone with a bulletproof helmet or vest or whatever, or shoot through a wall or a car or whatever to hit someone behind, where JHP arn't so great. I dunno though!

[Deleted]

Again, I don't know anything about guns and stuff, just repeating what a friend who likes guns has said to me, but like.. Isn't that the thing that like... JHP is less likely to go through someone than FMJ, so if you have to defend yourself or whatever it is that Americans do, you are less likely to hit someone behind the person that you are defending yourself against. That, and keeping civilians using JHP instead of FMJ means they are less likely to be able to hurt a police officer wearing a vest. Meanwhile, isn't the army more about maiming a certain number of people and killing a certain number, so that like, the healthy people have to tend to the injured, so a more lethal round isn't always better, and in a military setting you are more likely to have to shoot someone with a bulletproof helmet or vest or whatever, or shoot through a wall or a car or whatever to hit someone behind, where JHP arn't so great. I dunno though!

Yeah, the old cold war attitude was to wound the enemy and tie down the Soviet logistics, an injured man may take up the resources of dozens of support staff. Nowadays though the Taliban mostly do not give a crap about a wounded man and will often leave him behind, since they have no logistics system worth mentioning the 5.56 round currently being used is considered outdated and inferior.

We are looking at alternatives though, trials are suggesting the 6.5 performs much better and has the added bonus of not needing a new weapons system. Change the bolt and barrel of the Rifle and you have no need to retrain an entire Military on a new weapon.

[Schmeebs]

I thought the military didn't use them due to the Geneva Convention, or some such agreement.

Hague Convention actually. A military that follows it is restricted from using any bullet that expands inside the body (All NATO members follow this convention).

A main reason for JHPs in police and Self defense use is the increased stopping power and Reduced collateral damage (a JHP won't go through a person and then hit someone else behind). You hit someone with a .45 Hollow point, they are going to go down, and a FMJ from any reasonably powered rifle or pistol will probably go through a person (and also goes through stuff like sheetrock).

[Deleted]

Yeah, the old cold war attitude was to wound the enemy and tie down the Soviet logistics, an injured man may take up the resources of dozens of support staff. Nowadays though the Taliban mostly do not give a crap about a wounded man and will often leave him behind, since they have no logistics system worth mentioning the 5.56 round currently being used is considered outdated and inferior.

We are looking at alternatives though, trials are suggesting the 6.5 performs much better and has the added bonus of not needing a new weapons system. Change the bolt and barrel of the Rifle and you have no need to retrain an entire Military on a new weapon.

I just think people should use the prettiest guns regardless of how good they are. http://upload.wikimedia.org/wikipedi...000_rifles.JPG Like these things are pretty, what do they shoot?

[Deleted]

I just think people should use the prettiest guns regardless of how good they are. http://upload.wikimedia.org/wikipedi...000_rifles.JPG Like these things are pretty, what do they shoot?

That is an F2000, which is a fine weapon but still uses the standard 5.56 round, fine for fighting a standing army but not so good if the enemy is not willing to surrender when wounded.

[Kalis]

I just think people should use the prettiest guns regardless of how good they are. http://upload.wikimedia.org/wikipedi...000_rifles.JPG Like these things are pretty, what do they shoot?

The link says they're Peruvian Navy, so they mostly shoot Communist guerrillas and drug runners.


I know they meant what type of ammo, so no need for anyone to point that out.