Re: Why don't cartridge names match measurements?
"..told that .38 and .44 were named after the rim diameter, not the bullet diameter (.357/.429 respectively) but this isn't true either."
You wuz obviously told wrong. The .38 and .44 designation was the original case diameter of the loaded ammo at the mouth.
Marketing demands there be some differences in labels to hold ammo purchasing confusion to a minimum, all the purchaser needs to know is to match what's stamped on his barrel to the label on the ammo box. (Such "confusion" for reloaders is meaningless, if a reloader doesn't know and won't learn what he's doing he should take up golf.) Thus, in factory loadings we have .223 bullets only for the .22 Hornet while in .224 bullet diameter we have the .218 Bee, .219 Zipper, .220 Swift, .221 Fireball, .222 Rem.(and .222 Rem Mag), .223Rem/5.56 NATO, .224 Weatherby, .225 Win. No big deal. ??