does the calibre of a bullet have direct correllation to its diameter?

Answer 1

Yes it does. That's what calibre means, as well as gauge which is used for shotguns.

Answer 2

That's the general idea, but it gets complicated. For instance, a thirty caliber rifle is probably going to have a .300" bore diameter between the lands, but groove diameter and bullet diameter will be .308". Some are .310" or .311".
There are lots of 22 caliber cartridges, as another example, with names from 218 Bee to 225 Winchester, all of which shoot .224" bullets, with the names different just to avoid one form of confusion while substituting a safer form. That isn't to say that all 22 caliber cartridges are .224", because there are a couple of obsolete ones that use .227" bullets.
Another point of divergence is the 38 caliber pistol cartridges. Once there was a cartridge of 38 caliber that was 35 caliber at its base, fitting into a cartridge that would have been a 35 or 36 caliber if the bullet had been of normal construction. Indeed the cartridge was later used in just such a fashion with a smaller-diameter barrel, and the nomenclature did not change. So now we have the very popular 38 Special, with bullets of .357-.358" diameter, not because it's that caliber, but because an ancestor was.
And if this isn't confusing enough, the British have some great cartridges made by taking an established cartridge of one caliber and changing the neck to a different caliber. For instance, one of the great hunting rounds of all time is the 450/500-3 1/4", made by necking the older 450 down to shoot bullets of about .410-.411" diameter. Note the parent case is named first, the new caliber second. A similar thing happens in the US, as with the 338-378 Weatherby Magnum, but the new caliber is first, the parent last.
So you'll get some vague idea from the name, but you pretty well have to know each cartridge on a case-by-case basis, if you'll excuse the pun.

Answer 3

The calibre of a bullet is it's diameter expressed in thousandths of an inch. A .50 calibre bullet is half an inch in diameter (500/1000 inches).

Answer 4

Yes, caliber generally is a measurement of diameter. A .223 bullet is .224", while 9mm, .357, and .38 caliber bullets are .356". A .30-06 is a .30" bullet, and the cartridge was developed in 1906, thus the 'ought six'.

Shotguns are generally measured in gauge, which is a measure of how many lead balls of that diameter make up a pound. Twelve 12 gauge lead balls would equal a pound, and the diameter of those is generally accepted to be approximately .73". As the number goes up, the barrels get skinnier. A .410 shotgun is an exception, as it's measured in inch caliber, and it's diameter is .41".

Answer 5

The caliber does but the name of the cartridge doesn't have too. The company that manufactures the cartridge can call their product anything they want to and most do. As mentioned the .40 S&W, 10mm and the 41mag. are the few that are close to the actual caliber of the bullet. Don't try to go by the name of the cartridge, such as asking for some 303's and wind up getting 303 Savage instead of 303 British. Find out exactly what your rifle, pistol, shotgun shoots and buy only cartidges that are for that gun.
Sarge

Answer 6

No. The only calibers that are actual bullet sizes are .40 S&W, 10mm, and .41 magnum.
Other calibers are generally different than the designation to fit the grooves of the bore.
Most .30 calibers use a .308 bullet. .303 British uses a .311 bullet.
All calibers between .218 Bee and .225 Winchester use .224 diameter.

Answer 7

yes it does. For example, a .223 bullet would be .223 inches in diameter.
European rounds and military rounds are usually measured in metric.
You can use a micometer to tell the exact diameter of your bullet.

Answer 8

sometimes its close other times not examples,44 mag is .429 or 43 caliber.---38 special is .357 or 36 caliber---38-40 Winchester(also called38wcf) is .400 caliber ---44-40 Winchester is.427 or 43 caliber.etc.
so I guess the correct answer to your question is NO. there is no exact correlation,just approximations, sometimes based on the parent case,sometimes to differentiate between similar rounds

Answer 9

yes the 9mm bullet is 9 millimeters across. the .45 colt is something 45 across. it is actually what caliber means. At least, that's how it was explained to me.

Answer 10

Yes