How does caliber work?I always thought it was the diameter by length of the "bullet", but now I know that the bullet and cartridge are different things, and that the numbers refer to different things.Please help ty
>>64652314>diameter by length of the "bullet"E= Mc^2
>>64652314>#6 .338 spectre>10mm Mag necked for .338">.338ArcLiterally, nothing new under the sun.
>>64652314its literal definition in the context of firearms is the diameter of the bullet. in common practice its used to designate a specific cartridge. if i go into a gun store and ask for "9mm" everyone known im asking for 9mm parabellum and not any of the other meme 9mm calibers.
>>64652348This is true in theory, though a lot of cartridge names are just that--names--the numbers are not exact.For example, .44 Magnum uses .429 diameter bullets.
American naming convention>xxx *word*>example: .308 WinchesterBullet caliber in inches, followed by the company’s name, or wildcatters name, or something cool sounding like “blackout”Metric naming convention >X.XX x XXmm>example: 7.62x39mmFirst number is bullet diameter, second number is case length, both in millimeters .Metric contains more information and is ambiguous less often.But not all cartridges are in strict adherence with one of these conventions. 6.8SPC (#8 in your picture), for instance, follows the American Template except bullet diameter is given in millimeters. Then there’s weird shit like 25-45 Sharps where units are mixed. “25” is bullet diameter in inches (0.257”), but “45” is case length is millimeters. Some wildcatters just really need to differentiate themselves from everyone else.If we devised a trinomial naming convention where the volume of the powder charge were also contained, that would tell you quite a bit more about the cartridge. Far more than just case length. It would convey Total energy, sectional energy, trajectory and penetration characteristics, appropriate barrel length, recoil. All that. We don’t really have to include case length. Overall length is more important and there are only a couple standard action lengths, so appending A,B,C,D for action length in the end works just as well,
>>64652333Bro you don’t get it. 338 ARC is “advanced”. It’s hornady’s stroke of genius. Their brilliant ballisticians toiled day and night to produce the most mathematically optimal cartridge. Ditto with 26, 25, 24, and 22 sneed. These are groundbreaking cartridges and a paradigm shift in guns is no doubt imminent as a result.Fucking Hornady, man. They should’ve stopped with 6ARC.
>>64652389>Metric naming convention>>X.XX x XXmm>>example: 7.62x39mmNot always, you know that.>.44-40>.30-30>.30-06
>>64652402>338 ARC is “advanced”.To be fair, "advanced" is literally in the name. And why didn't they do a .400Arc? They laid up and dropped the ball.>inb4 too close to .338Poor sales guy has a boat payment, you know.
>>64652314in small arms it's the bore diameterin artillery it's (barrel length/bore diameter)
>>64652412Won’t someone please think of the poor sales guy and his 5th house and 3rd boat?
>>64652424I would buy a .404Arc if it was marketed with Teddy's pose from Mt. Rushmore and a lion on the box. All in, baby! Oh, and a matching carbonfiber Safari AR.
>>64652369>>64652413>in small arms it's the bore diameter>.429" is .44" groove measured from the landsCheckmate.
Brb ordering 50 cal rounds to reload my 500 S/w with. Shipping looks fucking insane.
>>64652432>>.429" is .44" groove measured from the landsLand vs groove diameter does explain why some cartridges names don't match their actual measurements, but that's not the case with .44 Magnum. Old .44's in the days of the old west did indeed use .44 diameter bullets, but those were heeled bullets. When the cartridge designs were modernized and no longer used heeled bullets the diameter changed but the name didn't. Note that .44 magnum brass measures .44 at the case mouth. That's where the .44 measure comes from, it's not groove diameter.
>>64652314I'll take 5.45 since m855a1 isn't on there, don't want that israeli mk262 dog shite.
>>64652412Wincheeser beat them to it and it'd require a different basic case extrusion that they're not tooled up for unless they were to tool up for a longer bullet only usable to make up for the shorter basic case they have in production. It's really cheap to make a new cartridge when you have 95% of the tooling already on hand, which is why they have every flavor of arc and sneed available. >>64652432It's usually .420 land to land for .429 stuff, which is why I call my .30-06 based .429 wildcat designed for AR10s (and other short actions) the .420 Blazer®™ Patent Pending no steal
>>64652413No, in artillery it's still bore diameter. They just often give the barrel length as well, measured in calibers. So a 155mm/L30 gun has a bore of 155mm and a length of 155mm * 30 = 4,650mm.>>64652314Caliber is nominally the diameter of the bullet, but it's also sort of a marketing term and doesn't necessarily correspond to anything. >For example, .50 BMG and .510 DTC are essentially the same cartridge, but .50 BMG measures across the lands of the barrel and .510 DTC measures the diameter of the unfired bullet. >Then you've got .22-250 Remington, .220 Swift, .221 Remington Fireball, .222 Remington Special, .223 Remington, and .224 Valkyrie. All four use the same .224" bullet, they're just given slightly different numbers to help distinguish them. For a bit of added fun, 5.56x45 is the official NATO designation for. 223 Remington, and 5.7x28 FN (also a NATO standard cartridge) uses the same .224" bullet diameter. This is another example of lands vs grooves.>And as a final example, .357 Magnum and .38 Special use the same .357" bullet diameter, while 9x19 Parabellum and .380 ACP both use a .355" bullet, and 9x18 Makarov uses a .365" bullet.There's lots more of these sorts of examples, some of them quite common. But basically, the nominal caliber of the bullet just gives you a rough idea of the bullet diameter, and cartridges are often referred to in terms of (caliber)x(case length). So 5.56x45 has a bore (across the lands) of 5.56mm and a case length of 45mm. This can give you an idea of the power of the cartridge, since most full power cartridges are over 50mm long and most pistol cartridges are under 30mm long.
>>64652406>.44-40>.30-30>.30-06None of those are metric, genius. What you meant to say was:>6.5 Sneedmore>6mm ARC>7mm-08
>>64652512No. .30-06mm.44-40mm.30-30mmAll work.
>>64652543None of those are real cartridges. As far as I know, there is no existing firearm with a bore of less than 1mm.
>>64652497Why do they give the barrel length? Is it meant to refer to the whole system? Does every artillery shell usually have only one specific gun it’s chambered in?
>>64652613Why ask a random panel of anonymous people when you can look it up faster and better than the replies you'll get.Do you need me to teach you the alphabet so you can start to learn things on your own like a big boy?
>>64652642Because we're having a discussion here. It's fun.
>>64652613For the same reason you see people talk about 11.5" or 14.5" or 16" or 20" barrels in rifles. I don't know why they're expressed in calibers rather than an absolute dimension, it's just one of those weird things like how metric tire sizes are expressed as (width in mm)/(aspect ratio)R(inside diameter in inches) where aspect ratio is {(OD in mm minus ID in mm)/(width in mm)}*100, while there's still a couple of American tire manufacturers that give their dimensions as (OD in inches)/(width in inches)R(ID in inches). The metric standard seems kind of convoluted and silly, but as long as everyone uses it, it gives you a good idea of the relative sizes of two different tires/gun barrels without actually having to do the math to determine how tall/long they are.
>>64652497>but it's also sort of a marketing termSometimes the marketing wank is very strong. For example .480 Ruger is a large revolver cartridge. By name only it sounds like it's bigger and badder than .475 Linebaugh, another big revolver cartridge, but in reality it is a shorter, weaker, version of .475 Linebaugh.
>>64652642> random panel of anonymous peopleAnons here are not just “random people”, you irreverent traitor.
I personally think its so gay that we do bullet diameter x case length it should be the length of the entire cartridge imo
>>64653059That couldn't be standardized tho, projectile length varies
Dont forget calibers that are named after the space between the lands in the bore and not even the fucking bullet itself.Late 19th-early 20th militaries were trolls
>>64652613>Why do they give the barrel length? That defines a lot of the internal ballistics>Is it meant to refer to the whole system? No - most large guns are fitted onto a variety of platforms with different recoil mechanisms>Does every artillery shell usually have only one specific gun it’s chambered in?No - as a matter of fact NATO, Korea and Japan all use interchangeable 155mm shells and propellants, but with different performance out of each weapon + projectile + propellant + fuze combo. Keeps the firing tables people employed.
>>64653179Overall length is standardized, though. 5.56 has a specified OAL of 2.260", for example. Of course, you can handload to whatever OAL you want but manufacturers load to SAAMI or CIP specs.
>>64653276>manufacturers load to SAAMI or CIP specsOAL is a tolerance band. Manufacturers load to whatever the fuck they want within that band.Look at .300blk, it's all over the place.
>>64652543LolLmao
>>64653243> That defines a lot of the internal ballisticsI know, but what is the point of including that in the cartridge’s designation? What if I called it 5.56-16” or 5.56-10”? It’s the same cartridge.
>>64653340The shells are just 155mm or 203mm or whatever. It's the guns that are named by the bore and length.
>>64653340>>64653348Also, since you don't seem to be aware and it's sort of relevant, artillery shells aren't actually cartridges. The projectile is a separate piece and then bag(s) of propellant get added in behind it.
>>64652389As a low IQ gun enjoyer this was actually an interesting read. Thanks high IQ anon.
>>64652389>Then there’s weird shit like 25-45 Sharps where units are mixed. “25” is bullet diameter in inches (0.257”), but “45” is case length is millimeters..25-45 was named to invoke nostalgia for older cartridges like .30-30 and .45-70 that were named for the bullet diameter and the nominal powder charge in grains. Which is actually more useful information than the case length, since case length is mostly used as a proxy for volume.
>>64653296>Look at .300blk, it's all over the place.>basically a wildcat roundmeh, its different from actually standardized ammo supported by many companies and governments
>>64653059>bme reloading>seats projectile to deep>i invented a new cartridge!>world: rrrreeee!
>>64652642I resent the assertion that I am "random". I AM NOT RANDOM.
>>64653059>bullet diameter x case length.250-3000, checkmate.
>>64652686My fav was always .257 Roberts. Designed back in a day when a guy in his shed could just invent new rounds, because.
>>64654625> Designed back in a day when a guy in his shed could just invent new rounds, becauseYou can still do that. But there are so many different chamberings out there that in all likelihood, you’d be duplicating some already extant cartridge.
>>64652389>>64652497ty anons. it's complex but also very simple
>>64652406Yeah not all cartridges adhere to either American or metric conventions. But the majority do.I gave it some more thought and came up with this trinomial naming system:>term 1: caliber in thousandths of an inch>term 2: case capacity in grains >term 3: action length, via a letter corresponding to the 4 or 5 standard action lengths 5.56x45 becomes 224/31A“A” corresponding to the 2.26” action lengthThis contains like 10x as much information as either of our current naming systems.>caliber>energy>sectional energy/trajectory/penetration>recoil>appropriate barrel length>barrel life>the guns that chamber it
