chat with the super

firefly08

Actually, the measurements used in naming the calibre are often not precise:

http://www.chuckhawks.com/rifle_bullet_diameter.htm

Note the various .3xx calibres that all use a .308" bullet. Also, the .303 British apparently uses a .311" bullet. Interestingly, the Russian 7.62mm calibres use .311", but the NATO 7.62mm is a .308"!

But the funniest thing of all is that it seems several of the .22 calibres use a .223" bullet, but not the .223 Remington, which of course uses a .224" inch bullet

I think the reason is that sometimes they use the measurement of the bullet, sometimes the diameter of the bore, and sometimes the diameter of the rifling.

But then, sometimes, they don't use any of these, they use the diameter of the cartridge case instead, eg. 38 Special, which is really a .357" inch bullet.

edit: didn't see Mr. Fibble's post

fodda

You are correct i just checked some out on Wiki and in some the name bears no relation to bullet diametre which is very strange. I thought old Whitworth was smack on in engineering? seems to get more confusing:o

Sorry missed a poster.....Old Joe Whitworth if anybody had an engineering background would know he was the man who invented threads for screws etc, the most famous the Whitworth thread, but he also invented a rifle bore/bullet/calibre and started the whole calibre thing off or is credited with it i think anyway

Sparks

firefly08 wrote: »

Also, the .303 British apparently uses a .311" bullet.

Well, technically, it uses a .311-ish bullet in a .303 calibre (the British calibre at the time was measured between the tops of the lands rather than the bottom of the grooves as we measure it today). But the thing is, as Mr.Fibble said, it's best to think of these calibres as names, not numbers, as their names can sometimes be misleading if you assume they're accurate measurements of the round...

dan17

years ago when all i had was two shotguns and a .22 i bought a .17 rem centerfire. the firearms officer rang me and asked...is that smaller than a .22....we will give ya a liecence on that no bother so...2 weeks later i had it home...well hope they say the same now when im looking for a 204:D

Grizzly 45

Sparks wrote: »

But the thing is, as Mr.Fibble said, it's best to think of these calibres as names, not numbers, as their names can sometimes be misleading if you assume they're accurate measurements of the round...

30.06 being a fine example. 30 caliber introduced into the US army in the year 1906.

tac foley

fodda wrote: »

For those who dont know, the .22 or .303 .223 etc comes from the old British Imperial measurement which was and is perfectly correct before the EU forced decimilisation on us. If your cert is .22 inches or .220 inches then this is correct as .22 or .220 means 220 thousands of an inch diameter, and .223 means 223 thousands of an inch diametre and .303 is 303 thousands of an inch diametre.....same goes for .38, .45, .357, .50, etc etc etc.

Thousandsth of an inch was and is an extremely accurate way of measuring metal in engineering terms, and the thickness of a human hair was around 2 thousands of an inch.

Showing my age:o

Got no hair left to measure, me.

tac

SpringerF

And to complicate things even more, rifles named as the same calibre depending on *where* and *when* they were manufactured can be of different sizes.

EG .22 Hornets are a different bullet size pre 40's or 50's ???

the current Hornet, at least my one, is .222
The older one I think was a .224

There are still lots of these old Hornets around the world.
Thanks be to reloading !!!!!!!!!!

gunning84

anyone know after having chat with super how long before you find out if its granted,ball park would do?

Odysseus

johngalway wrote: »

I think that was standard on the old licenses, probably not much different on the new. My .22lr was down as 220 Inches :rolleyes:

My current .220 air-rifle license is also down as .220 too.