Originally Posted by CavScout
This has probably been asked a billion times, but what does the -06 mean in .30-06 (and .25-06, etc). My understanding is that the projectile in the .308, .30-30, .30-06, 300WM, etc is really close to the same diameter (although they are not interchangable, I know that). So what does the number after the dash mean?
The "06" stands for the 30-06's apoption date by the military (pronounced "ought six")..and before that, there as a slightly longer necked/round nosed bullet using 30-03 (bit its' kind of rare as most of the rifles got converted to the 30-06).
Some calibers built on the 30-06 casadapted the "06" part of the name (as in 25-06).
The numbers in most of the caliber names doen't mean much of anything, just marketeind and a "sound good" kind of thing. .218Bee, .219Zipper, .220 Swift, .224Weatherby, .225 Wincester all use standard .224" bullets....the .22 Savage (also called the .22 High Power) uses .228" bullets...but the .22Long Rifle rim fire and the .22Jet centerfire (handgun round) both use .222" bullets. See...no real relationship between bullet diameter and name.
Don't know why the 30-30 got that name..it was never loaded commercially with black powder, so the second "30" is probably just left over from black powder designations (same is true for the 25/35).
Before smokless (back in the 1800's) it wasn't a little bit better. The common way to designate a round was by caliber-and black powder weight -and often by bullet weight. So you'd get things like the 45-70-500 or 40-82-260. But mixed in were "name" round sthat didn't have that numeric information (.44 Henry, .44 Evans, .44 Evans Long, 58 Miller, etc.)...and you'd have some folks tha nemaed them ack-basswards like the 56-46 Spencer where the SEOND number is the caliber.
Don't get me started on metrics.
Back to the "ought six"...as time has come full cirle and we are back in dates ending with 04, 05, etc. We've seemed to just go with "oh five" rather than "ought five"...this is nice, will keep future generations from confusing the 1900's and the 2000's .
We've almost compeltely droped the "nought" for "zero". Wihc leadsme to the only other survivor of the "ounght years" are the names for buck shot ("double ought", etc.) and possibley the corrupted "do nut" ( which was once a dough nought).