Home Forums Hunting & Shooting Alaska What do people mean when they say Caliber?

If you’re talking to a Navy gunner, caliber is the length of the barrel using the diameter of the shell for reference. E.g. a 3”x 50 caliber gun has a three inch bore and the barrel is 3x50 or 150” long.

And so again caliber refers to dimensions and not a cartridge.

Hole or projectile size............ is what I mean when I say it.....

So again, confirmation that caliber refers to dimension and not a cartridge.

It would be a toss-up for me, between Starrett and Brown and Sharp. My 12 inch is a Starrett, but my 6 and 8 inch are both Brown and Sharpe.

When someone says "caliber" when they mean "chambering" or "cartridge,"
I always check to see if they are wearing a nose ring or nostril stud.
Sure signs of low IQ.

With calipers you can measure calibers and cartridges. Heck, you could even use calipers to measure the clip on your magazine, but you can't use calipers to measure speed OR velocity.

Yep.

There was "caliber" before there ever was a ctg.

There is a lot of misuse of terminology, but we generally understand what is being conveyed when someone talks about the "caliber" of his weapon.

Misuse of terminology doesn't bother me nearly as much as it bothers some.

DF

Maybe, maybe not...

We call a .284 diameter a 7 mm. But .277 actually is closer (almost exactly) to 7 mm. Don't believe me? Measure a .270 bullet with a caliper that has English and metric scales, then toggle between English and metric to see.

I have wondered why for a long time. The reason is probably buried somewhere in history...does anyone here happen to know how this came to be?

The hole size, or bore size is either 280 or 270, so which is closer to 7mm............?????

We're not talking, groove size or projectile size..................

The short story, overview is marketing competition between Winchester & Remington. It was long accepted that the 470 NITRO was the go-to cartridge for culling small herds of Elephants. But the Double rifles, and that cartridge were expensive, and not conducive to the dangerous work. What was needed was a bolt action firearm and new cartridge, that were much cheaper and safer for culling "large" herds of Elephant "safely". But the cartridge needed to mimic the 479 NITRO.

Winchester created the .458 Winchester Magnum cartridge, which matched the ballistics of the 470 NITRO.

From there it was wide'ass open competition to neck the .458 Win. Mag. case down into wildcat cartridges. Winchester was still gloating about their new wonder cartridge, and was a sleep while Remington necked that case to 7MM Remington Magnum. (Winchester totally screwed up in creating cartridges based on their .458 WM case. To play catch-up they produced the .264 Win. Mag. but introduced it with the wrong barrel twist rate (which was a "massive" marketing FAILURE).

The "only" thing Winchester did RIGHT was the .338 Win. Mag. Winchester should have introduced a cartridge in 30 caliber cartridge based on the .458 Win Mag. But yet again they were sleeping, and Norma introduced the .300 Norma cartridge, totally based on the ,458 Win. Mag. case. Winchester was compelled to design a slightly different case for their .300 Winchester Magnum. Purely dumb'ass luck the new case and cartridge was a thundering success. In part because the case was .062 longer, and in marketing "Bigger" means more powerful, and more powerful sells.

It's a dimension

Nope, apparently we are talking about the land-to-land diameters. The .270 projectile diameter, and groove-to-groove bore diameter are both actually .277 of an inch. If you take a conversion chart and do the math, .277 is almost exactly 7 mm. It's easier to set an English/metric caliper to .277 inch and then change the scale to metric and see what appears. If the lands are about .035 "tall" on each side, then the land-to-land diameter would be .277 - .007=.270.

And the new ammo in development for the Army now uses .277" bullets, but with the designation 6.8 mm, as in 6.8 SPC. .270" is pretty close to 6.8 mm.

The "7 mm" projectile diameter and groove-to-groove bore diameter are .284. The land-to-land diameter is about .277 and this may be how the .284 came to be called a 7 mm. I may have answered my own question.