Reader Anner writes:
True Believers get all wrapped up in proper firearms terminology. Avoid that next lecture from the old coot behind the counter by studying this partial guide to proper firearms terminology:
Caliber – The diameter of the firearm’s bore, expressed as a fraction of an inch. “.30 caliber” is 3/10 of an inch wide. Depending on manufacturer’s specifications, this may denote the diameter of the bullet, cartridge mouth, barrel lands, or barrel grooves. Europeans generally measure barrel lands, while American manufacturers use barrel grooves (which is usually the actual bullet diameter). When ammo manufacturers create a new cartridge, they need it to sell. They will often choose a name that does not accurately describe its actual size. For example, .223 Remington is actually a .224” bullet; .300Blackout is actually a .308” bullet. Reference a reloading manual or the manufacturer’s website for accurate specifications . . .