meaning of calibre

[bhuwan]

HI GUYS!
What does calibre mean and what is the difference between .177 and .22 calibre?
bhuwan

[Mack The Knife]

Calibre refers to the diameter of the projectile or the bore of the rifle or gun.

.177 calibre refers to .177" or 4.5mm dia and .22 calibre refers to .22" or 5.5mm dia

[penpusher]

If you are not satisfied with the explanation given by Mack The Knife,things will become very confusing very quickly Many times the given caliber is not the actual bore diamete.Sometimes 2 seemingly different caliber firearms are in fact of the same caliber and and vice versa.Welcome to the mad mad world of firearms in which the unwary and the stupid have every opportunity to blow themselves up Lots of them in India including a large percentage of the so called 'gunsmiths'.

[mundaire]

If you are not satisfied with the explanation given by Mack The Knife,things will become very confusing very quickly Many times the given caliber is not the actual bore diamete.Sometimes 2 seemingly different caliber firearms are in fact of the same caliber and and vice versa.Welcome to the mad mad world of firearms in which the unwary and the stupid have every opportunity to blow themselves up Lots of them in India including a large percentage of the so called 'gunsmiths'.

Not to mention "phantom" calibres that people dream up from time to time

Cheers!
Abhijeet

[Grumpy]

"What does calibre mean and what is the difference between .177 and .22 calibre?"

It means that one is bigger than the other........I`ll leave you to figure which is which but Mack The Knife provided the clues.

penpusher, don`t confuse the chap......He doesn`t need to know that a .357 magnum is the same calibre as a .38 Special........or that a .303 Enfield is actually c.311"........or that a .44 mag is .429 calibre. There are so, so many examples.

Ah yes, the imaginary `phantom` calibres.......just like the imaginary phantom manufacturers. Bhuwan, just remember that when in doubt the answer is always `BSA` or `Purdey`............... apparently.
LMAO !

[Grumpy]

"Welcome to the mad mad world of firearms in which the unwary and the stupid have every opportunity to blow themselves up Lots of them in India including a large percentage of the so called 'gunsmiths'."

Yup, I`m looking forward to someone trying to stuff a .50 BMG down a .500 BPE - That will be spectacular !
"The bug*3r won`t fit". "Well just give it a tap with a hammer" !!!

[Pran]

>He doesn`t need to know that a .357 magnum is the same calibre as a .38 Special........or that a .303 Enfield is actually c.311"........or that a .44 mag is .429 calibre. There are so, so many examples.

Was unaware of that too. Why would someone specify different bore dia and projectile dia for the same gun?

Pran

[Grumpy]

"Why would someone specify different bore dia and projectile dia for the same gun?"

Er.....................Pran, just how did you manage to leap to that conclusion ?

In the case of the .357/38 that means the bullet would fall straight through the barrel........or, if vice versa, the bullet would jam in the bore.
There IS a slight difference between the bullet diameter and bore but only a couple of thou.
The reasons for the difference between the quoted and actual calibres are various. It has been known that the lands were measured instead of the flats......or vice versa. It might be because the PR wallies thought that `.44` sounded more butch than `.429.` It`s possible that bore gauges used to be very inaccurate..............It could also be the case that the the designations were applied by idiots. It`s definitely the case that I don`t know why the actual and designated calibes are so often at variance.
I used to know the the story of why the so-called `.38` is actually .357 but have forgotten it.
The point penpusher was making is that: a. The designated calibre is often not the actual calibre ; b. Just because two cartridges/share the same calibre designation it does not mean that that share the same actual calibre; c. Cartridges/rifles sharing the same calibre designation invariably do not share the same chamber/case size and d. A combination of the above.
Using an incorrect cartridge in a rifle can be a fatal mistake........and invariably an expensive one.
That`s why cartridges of the same ( designated or actual ) calibres are often further qualified to indicate the chamber/case length along with other designators. ie. 6.5x54 M-S ( also know as the 6.5x53 and 6.5x52 ) and 6.5x55 Swedish . 7.5x53.5 Swiss, 7.5x54.5 Swiss and 7.5x55 Swiss.......and so on and so on and so on. Chamber a 7.5x55 in an early Shmidt Rubin rifle chambered for the 7.5x53.5 ( and the longer case WILL chamber in some worn chambers ) and the result will almost certainly be a lump of scrap metal.
There are much better known examples, particularly the 8mm Mauser where there is a very dodgy situation because the rifles chambered for original 8x57I will happilly chamber the later 8X57JS which developes MUCH higher pressures.....a situation componded by the fact that the later rifles had a larger ( .323" ) bore and bullet size than the early ( .318" ) examples. For this reason the US SAAMI loading/pressure specs for all 8x57 ammo are based on the 8x57I..........and therefore rather gutless wonders. In Europe we reckon that people should use their common sense so ammo is loaded to 8x57JS specs........ So it`s a very good idea not to use European 8x57 ammo in your early Mauser.
Check out the Woodleigh bullets website and note the actual bullet diameters compared to the designated `calibres. Handgun cartridges can be much more extreme.
http://www.woodleighbullets.com.au/Bull ... t%203.html

[cottage cheese]

Not to mention "phantom" calibres that people dream up from time to time

Ha!!

I once read news clipping that mentioned the seizure by some police, of a 9Km sten machine turbine...

Of course when you hear a senior cop speaking of "9.62mm Russia made Mauser Pistol gun" in a press conference, you can say our country has lost it!!

[penpusher]

My father once asked a constable who had been sent in place of the regular bodyguard,who was on leave,as to what firearm had he been issued.His reply", 12 bore pistol". He had a 9mm pistol.

Remember a comment by late Rajiv Gandhi,when he was the PM ,that guns of the Delhi police constables assigned to protect the perimeter of the PM residence,going off accidentally was something very common.

I have also seen a .380 Llama that was destroyed as the fellow,an army officer, had fired a 9mm para cartridge from it.Those who call Spanish pistols as being made of soft steel,please note.The barrel had bulged,the slide had almost come off the frame which too was bent.However everything held together and the pistol did not transform itself into a hand grenade.

[Pran]

>The reasons for the difference between the quoted and actual calibres are various. It has been known that the lands were measured instead of the flats......or vice versa. It might be because the PR wallies thought that `.44` sounded more butch than `.429.` It`s possible that bore gauges used to be very inaccurate..............It could also be the case that the the designations were applied by idiots. It`s definitely the case that I don`t know why the actual and designated calibes are so often at variance.

>a. The designated calibre is often not the actual calibre ; b. Just because two cartridges/share the same calibre designation it does not mean that that share the same actual calibre; c. Cartridges/rifles sharing the same calibre designation invariably do not share the same chamber/case size and d. A combination of the above.

Thanks. Found it very informative.

Pran

[penpusher]

Yup, I`m looking forward to someone trying to stuff a .50 BMG down a .500 BPE - That will be spectacular !
"The bug*3r won`t fit". "Well just give it a tap with a hammer" !!!

Funny that you should say this as I know of a fellow who managed to put in 2 cassettes into a VCR.Tried to push in a tape and did not realise that there was already one in it.Pounded on the tape that he was pushing into the VCR with his fist and finally managed to push it in.Predictable results Would be impossible getting a 50BMG cartridge in India.However a 500 Jeffery or a 500NE in a 500BPE rifle is certainly a possibility

[Grumpy]

You mean the Indian army haven`t got any .50 cals ? I`ll bet that they do.

Yeah, a .500 Jeffery in a .500BPE would be rather good......I`d like to see it done........but from a good distance !

As it happens there`s no way that a .50 BMG will chamber in any .500 sporting rifle as the case diameter is far too great - it was was by way of being an exaggerated example of the point I was making.

[art_collector]

My father once asked a constable who had been sent in place of the regular bodyguard,who was on leave,as to what firearm had he been issued.His reply", 12 bore pistol". He had a 9mm pistol.


I have on occassions seen retired army personel with valid NPB gun licences asking for 303 gun ..........so a 12 bore pistol is not a very suprising answer.

Many army personnel get a civilian arms licence for a gun and become security guards...99% don't know how to operate a gun or assemble it....and most of them place their fingers on the trigger while loading it.

[shahid]

There are firearm licences issued with calibre mentioned as .12 Bore gun.

That would mean even smaller that .22 LR or an air rifle.

Anomalities are common.

People try to fire 6.5 x 57 cartridges in 6.5 x 54 MS rifles. There are so many such cases.

Another confusion lies between 8 mm, .32 and 7.62 Automatic pistol cartridges.

THe S & W long cartridge has been purchased so many times by people with normal Browning type 8 mm firearm.
9 mm firearms too have a long list of sizes and chamberings and equally big confusions.