Carl, here's part of a short article I wrote on this subject a year or two ago:
In 2017 I started collecting firearms websites that use caliber when they should use cartridge or chambering. You’d think shooting industry folks would know better, but here’s the list—though some companies (including Hornady and New Ultra Light Arms) have apparently heeded the calls for caliber correctness since I started the list:
Barrett Firearms
Federal Ammunition
Fierce Arms
Franchi
GA Precision
Heym
Hill Country Rifles
Holland and Holland (calibre)
Hornady
Howa
H-S Precision
Kimber
Lapua
Lyman
Mauser
New Ultra Light Arms
Norma
Rigby (calibre)
Ruger
Sako
Sauer
Shaw Barrels
Smith & Wesson
Speer
Tikka
Weatherby Rifles
Winchester Rifles
Listing caliber-incorrect websites, however, might imply this is a recent development, caused by the general semi-literacy of the Internet. But it’s apparently traditional—and sometimes perpetrated by revered members of the shooting profession.
Col. Townsend Whelen, perhaps the best-known American rifle writer during the first half of the 20th century, misused caliber quite a bit, even well into the second half of the century, doing so several times in the 1965 book Mister Rifleman, co-authored with Bradford Angier. Ken Waters, the long-time “Pet Loads” columnist for Handloader magazine, published a column on the .300 Weatherby Magnum in 1971, where he stated the barrel on his rifle is “the No. 1 contour barrel, standard in Weatherby Mark V rifles of this caliber.”
The English language complicates this by being more flexible than some other languages. German, for instance, tends to be pretty rigid, especially the written form, though major controversies have erupted over recent attempts at uniformity. The German orthography reform of 1996 (Reform der deutschen Rechtschreibung von 1996) simplified and sometimes deleted older rules, such as capitalizing all nouns. But so many traditional Germans rebelled that a decade later the Council for German Orthography reversed many “reforms,” including capitalizing nouns.
American English is far more flexible, largely due to Noah Webster. His original 1828 American Dictionary of the English Language (which Webster called Federal English, as opposed to British English) was based on his belief that spelling, grammar and definitions should be based on how most people actually spoke and wrote—which is how he came up with his commonly understood meanings.
“Caliber” is so commonly used for cartridge and chambering at least 90% of us wouldn’t hesitate when somebody takes a look at one of our rifles and asks, “What caliber is it?” Instead of arguing about the meaning of caliber, we’d reply .243 Winchester or .30-06 or .375 H&H. Only the other 10%, who firmly believe there’s ONE definition of caliber, get as upset as traditional Germans who know nouns MUST start with a capital letter. (These percentages are just guesses, of course. In my experience the percentage of caliber Websterists is probably higher, perhaps even 99%.)
Of course, caliber-correctness has not died, despite widespread changes in American common usage since we rebelled against the British government. This is why you probably won’t see any of my articles describe the .270 Winchester or .300 Weatherby as a “caliber.” However, I am getting older and more forgetful, so won’t guarantee anything—though I still believe ranting against the “misuse” of caliber resembles trying to block a tidal wave with a sand castle.
