As always, Mister Nifty, please do not confuse me with someone who knows squat. I'm just asking questions.
According to Franklin Mallory in his book, THE KRAG RIFLE STORY, the choice was arbitrary, merely copying what most European counties were doing, using from 7.5 to 8mm diameters for their military cartridges at the time.
The Spanish-American War proved the worth of the 7mm bullets (.284") in the 7x57 Mauser rifles, yet, despite serious consideration, the US chose to stick with the .30 caliber when it developed the rimless 30-03/30-06. That American attitude of "bigger must be better," evidently won out.
Weren't all the world powers pretty much being arbitrary? You've got this period of the 1890s to 1910's, where everyone pretty much settled on their caliber of choice for the next 60 years and some folks picked 6mm, some 6.5, some 7, some 8.
I happen to be somewhat of a 30-something snob. I know it. I pretty much wallow in it. I can also tell you why, and very of it has anything to do with rational thought. I can see guys all over the world with powder burns on their lab coats coming up with similar conclusions in pretty much the same way.
I also wonder here about the Mauser Brothers. I'm scratching my head. On the one hand you've got them developing the basic idea for the ultimate bolt-action military and hunting arm ever conceived. Somebody has been shooting a Mauser design at their enemy since just after our Civil War. It became the standard and has stayed the standard. On the other hand, the caliber and chambering remained pretty much a whimsical proposition. Mauser seems to have never tried to say, "Look here, guys. If you really want our rifles to perform well, here's this suggestion on bore diameter." The Germans pick 8mm. The Spanish 7mm, Swedes and Boors pick 6.5. We get all hot and sweaty on 7.62mm. You'd think -- if it were possible-- that someone would have done the research back then to figure out what the best was and standarized on it.
My guess is that there really isn't a possibility. For one thing, if you were to get the great minds of the late 19th century in a room to discuss the matter, they'd sound like the Barber Shop on Saturday morning. Nothing would get done. For another thing, you can make an argument for any caliber in the 6-8mm range, and you can make it work-- at least to take down a human-sized target out to as far as you can see with the naked eye. It ain't just about caliber. It's also about who has what kind of powder, what shape are the bullets you're testing, and the general size and capacities of the cannon-fodder you pick to test the weapon in field trials. We've been basically testing this question since the 1890's and we still cannot come to any meaningful conclusions. I suspect we never will.
Then again, there is .29. Mister Mule Deer might have something there.
