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Subject: Guns explained.
LogicRules    11/8/2003 12:46:09 PM
I hope someone on the boards could help me with guns and their caibre and other such gunstuff. For example what is a 9mm bullet?Is it the lenght of the catridge or bullet? and what is the .333 or other such numbers that follow a period when refering to guns? Thank you. I have posted on other boards but never recieved an comprihensible answer. The psters on this board seem a lot saner and understandable, so i hope i can find a answer here.
 
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ChdNorm    RE:Guns explained.   11/8/2003 1:52:29 PM
The first measurement in a caliber designation such as 7.62x51mm NATO for instance is the bore diameter measured in millimeters. the second number would be the length of the cartridge case. When you see a cartridge using a designation such as .308 Winchester (which is the 7.62X51mm NATO in commercial form) the bore diameter is still used as the measurement, only this time the unit of measurement is in inches rather than millimeters. Some cartridge names can be a little misleading in the inch form. Such as the .38 Special which has a bore that measures .357", or the .44 Magnum, which measures .429". Generally speaking the metric cartridges tend to be more accurately defined. I hope I've been of some use.
 
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LogicRules    Thanks Chdnorm   11/8/2003 6:01:29 PM
Yes you have. But then why is the 9mm considered a small calibre? or is it that the aerodynamics of such a large bullet makes it slow and therefore a less dangerous bullet? Also stuff like bullpup and lenghts of bores would be great. Thanks. (Oh yeh. Do fins really impart the same amount of spin as rifling? Is it better to have a smoothbore gun and use finned projectiles for direct fire, or is it better to have rifling if you know most engagements will be direct?) Any and all answers are welcome. thanks again to chdnorm.
 
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ChdNorm    RE:Thanks Chdnorm   11/8/2003 7:31:37 PM
But then why is the 9mm considered a small calibre? generally handguns use a larger bore diameter than rifles. Think in practicle terms as common rifles using bores of .22" up to .30" while adequate service style handguns use bores from .355" up to .45". Thats a practicle approach for the most common. There'slarger and smaller rifle and handgun just trying to keep it simple. Although rifles fire a much more powerful round by using considerably more powder to drive the bullet. In handguns, the 9X19mm NATO (AKA 9mm Luger, 9mm Parabellum etc) measures .355 in inches which is, by US standards, comparatively small. In Europe it isnt really considered that small. Traditionally European handguns used much smaller cartridges such as the .32 ACP and .380 ACP rounds in relatively small handguns. During that time period the US military used the .45 ACP round which dwarfs the others by comparison. I'm not sure of the theories or doctrines that led the differences, but I think citizens generally follow their given countries when choosing things like cartridges. To make things even more confusing though, during that same period the acknowledged standard of American law enforcement was the .38 special which was always considered adequate by most that used it. The .38 special (which even though is called a .38 actually measures .357" ... only 002" bigger)is ballisticly not that much different than a 9mm, but it isnt considered small although the 9mm is. To sum up my ramblings ... Americans consider it small, while pretty much the rest of the world considers it adequate. I think it suffers from some degree of predujice as its not a traditional American cartridge. A bullpup is s design of rifle that places the action behind the grip creating a much shorter overall length. Examples would be the Steyr AUG, British SA-80, FN2000,French FAMAS. look at them, I think pictures can desribe them much better than I can. I'm not really sure how to answer your last question in regards to fins. Off hand I'm not familiar with the use of fins to impart spin on a projectile. The only experiance in regards to something like that I have would be with finned shotgun slugs, which dont spin the projectile but attempt to merely stablized it. By comparison though, rifling seems to work much better.
 
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LogicRules    RE:Thanks Chdnorm   11/9/2003 7:02:17 PM
Thanks again. But in the short period of time between that answer and now i got a few more! How has kick been reduced from the gunpowder age? Is it becuase of man learning to direct the force of the explosion more exactly or is it something in the gun itself? Or maybe the powder mix? Also what bore size and such(generally speaking) are sniper rifles? and do shotguns have a rather large bore? Thanks again. i really appreciate you taking time to explain this for me.
 
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ChdNorm    RE:Thanks Chdnorm   11/9/2003 9:08:39 PM
How has kick been reduced from the gunpowder age? Is it becuase of man learning to direct the force of the explosion more exactly or is it something in the gun itself? Or maybe the powder mix? I take it that you are meaning from the black powder/muzzleloading days? Generally speaking recoil (AKA kick) has become more pronouced in modern firearms. It has mainly to do with the powder used. Black powder is very slow burning which creates a longer recoil impulse compared to modern (post 1890 or so) smokeless powders which burn very fast. Generally the results of that are that modern rifle cartridges fire much smaller bullets in both wieght and diameter, but at much higher speeds. There are designs and devices to help tame recoil. Everything from muzzle breaks mounted on the end of the barrel which redirects the gasses to offset the recoil to even hydrolic recoil devices mounted within the butt of a rifle or shotgun to absorb the recoil before it is transfered to the shooter. Also what bore size and such(generally speaking) are sniper rifles? There are no real standard calibers for sniper rifles, generally it depends on the intended mission. Law enforcement snipers will generally prefer a .223 Remington up to a .308 Winchester where ranges are short and other things become more of a concern (over penetration, noise levels, etc). Military snipers generally use a medium caliber such as a 7.62 Nato or 7.62 Russian where ranges tend to stretch into 600 meters. The US Army also be fields the .300 Winchester Magnum and the British use a .338 Lapua Magnum to augment the 7.62 NATO rifles for a little more range (800-1000 meters). Then you get into the really big sniper type rifles. These are chambered for the .50 Cal machine gun round and cartridges of similar size and power. These rifles have exceptional range. It is my understanding that several Canadian snipers in Afghanistan made shots on individual targets at close to or slightly exceeding a mile. Generally they are reffered to as anti-material weapons for use against light vehicles and other gear. and do shotguns have a rather large bore? The 12 guage measures approximately .73". The 20 gauge measures approximately .63". And the .410 gauge measures approximately .41" which is actually the measurement of the caliber rather than the gauge. That may sound confusing .... "gauge" is the number of that diameter round lead balls that will fit into that barrel diamter that equal a pound (12 lead balls measuring .73" in diamter wiegh one pound, therefore its a 12 Gauge). Caliber directly measures the bore diameter. Thanks again. i really appreciate you taking time to explain this for me No problem at all .... I actually enjoy a line of questions where theres no chance of me getting mad anout the French
 
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