When does a caliber become a magnum?

Is it velocity, ft-lbs or something as simple as just adding a belt? Oop's some magnums don't have a belt.

I'd say anything that has more than 50gr powder capacity.

.30-06?

I'd call the differentiation more art than science. "Magnum" basically means "we took a chambering that exists and took it to 11" or "we're Holland and Holland and we like that term"

The only real definition I know is when Champagne comes in 1.5 liter bottles.

A 17 HMR doesn't have 50 grains of powder.

Long actions with a bolt face .Dia of .540 +/-

257 Weatherby, 264 Win Mag, 270 weatherby Mag, 7mm Rem Mag, 7mm Weatherby Mag, 7 STW,
7mm Rem Ultra Mag, 300 H & H, 300 Win Mag, 300 Weatherby Mag, 300 RUM, 303 Brit,
8mm Rem Mag, 338 Win Mag, 340 Weatherby Mag, 338 RUM, 375 H & H, 375 Weatherby,
375 RUM, 416 Rem Mag, 458 Win Mag, and the 458 Lott.

Long actions with a bolt face .Dia of .585 +/-

30/378 Weatherby, 338 Lapua, 338/378 Weatherby, 378 Weatherby mag, 416 Rigby,
416 Weatherby Mag, 460 Weatherby Mag, and the 470 Nitro Express.

any chambering with at least .532 bolt face..... is a good start. The .284 and has standard BF"... but its a baby magnum

Its meaningless.

There are no rules whatsoever to naming cartridges. Half the time, they don't even name it by the right bore diameter.

Guess my 270 win just became a magnum.

Strictly in the name and nothing else. Example is .222 Magnum, short lived commercial round and was made extinct by the .223 Rem.

It becomes a magnum when the marketing guy advertising the new product adds it to the name.

Story goes when they came out with the .450 Marlin they originally were going to name it the .450 short magnum. However, Marketing decided it would stop buyers because they would associate it with African game calibers and super heavy recoil.

Magnum is just a name, some of the most powerful cartridges do not have Magnum in the name while some weak ones by comparison have Magnum. Look at the quarter bore 256 Winchester Magnum and 257 WBY magnum, both are named MAGNUM but one most here would not consider enough for hill country deer.

.22 wmr. Not very big compared to most magnums. Should have just called it the .22 extra long rifle!

When the marketing department decides that appending the terms "Jeroboam", "Marie Jeanne", "Tappit Hen" or "Tregnum" is silly.

Would you really shoot a .277 Weatherby Tappit Hen?

So it's a different marketing than used for Android OS names?

Alpha (1.0)
Beta (1.1)
Cupcake (1.5)
Donut (1.6)
Eclair (2.0–2.1)
Froyo (2.2–2.2.3)
Gingerbread (2.3–2.3.7)
Honeycomb (3.0–3.2.6)
Ice Cream Sandwich (4.0–4.0.4)
Jelly Bean (4.1–4.3.1)
KitKat (4.4–4.4.4, 4.4W.1–4.4W.2)
Lollipop (5.0–5.0.2)

I got a couple friends that brag about hunting with magnums or ultra mags...neither one of them can hit anything cause they are probably flinching when the shoot...but they can say they are hunting with magnums....ego trips I guess.

How tall are those friends?

how tall? in their minds or in reality? they are grown fair sized men.

I, myself, am greatly looking forward to Android MooseNose Damien ( 6.0 - 6.6.6). I hear it's a devil of an operating system.