.30-06 isn't obsolete and works fine. It is fairly poorly designed by modern standards, but then again there was a lot we didn't know about interior ballistics back then. If done over, it would be shorter, with a steeper blown out shoulder and higher MAP. Coincidentally, that's what the .308 is.
Higher MAP, perhaps. Shorter and fatter with a steeper shoulder, not necessarily. In fact, it could end up pretty much as it is now. It is interesting that the "poorly designed".30-06 is one of the most used cartridge cases for necking up and down. The .25-06, 6.5-06, .270 Win, .280 Rem, .338-06 and .35 Whelen are among the most popular offspring but there are others. This throwback to a 111 year-old design remains among the most popular cartridges, particularly for hunting purposes.
The .30-06 fills a "niche" so large it is inappropriate to call it a "niche". I won't claim it is the most useful cartridge but I don't know of any cartridge that deserves the title more.
The.30-06 use for wildcats was more an issue of timing and lack of other available parent cases than anything. It doesn't reflect any efficiency on the part of the .30-06 - which makes sense, since the .30-06 is on the inefficient side for a bottleneck cartridge. As to case taper and shoulder angle, there is exactly zero advantage to a high taper and shallow shoulder at this point. It's just a waste of case capacity and needlessly decreasing the efficiency of the capacity you do have for no good reason.
The .308 gets much of its oft vaunted “efficiency” through the use of higher MAP than the .30-06 (62KPSI vs 60KPSI). Load them to the same pressure and the .308’s “efficiency” proves to be rather ephemeral at best. In any case, efficiency is one thing you often sacrifice when striving for higher velocity. Load a .308 and a 30-06 to the same pressure with the same bullet and powder and you’ll get higher velocity with the .30-06. Alternatively, load both to the same velocity with the same bullet and powder and you’ll get lower pressures with the .30-06.
As a side note, the lower pressure of the .30-06 for a given velocity aids in longer brass and barrel life.
The .308 is great with lighter bullets but as bullet weight increases the extra case capacity of the .30-06 gives handloaders an undeniable edge when it comes to velocity. Loaded to at least the same pressure as the .308 Win, as one would assume would be done with a new cartridge design, the .30-06 becomes a “.308 Magnum” with no loss of magazine capacity.
You’ll note I did not say a “modern” .30-06 would be “identical” to the 1906 design but rather “it could end up pretty much as it is now”. Emphasis on the word “could” as it was an intential qualifier. No one knows what a “modern” .30-06 would look like unless or until one appears.
I’m not a big fan of sharp shoulders and straighter, and therefore marginally fatter, cases - they are something I would generally give up for a smoother feeding and easier extracting cartridge. I say “generally” because I did go with an AI with my custom 6.5-06. The reason the sharper shoulder and straighter case of the 6.5-06AI was chosen was not so much to maximize velocity potential as it was to prevent someone from trying to stuff one of my loaded rounds, which use .25-06 headstamped brass, into a .25-06 rifle.
The 6.5 Creedmoor is about as “modern” a cartridge as you can find. It is .2mm fatter at the shoulder than the .308 Winchester (zzzzzzzzzzzzzzzzzz) but the shoulder taper is so nearly the same I can’t tell any difference by looking at photos of the two. It is also shorter with less case capacity. It can push a 130g bullet to about 2700fps with carefully selected powders, By contrast, a standard 6.5-06 easily adds 200fps to that value with a wide variety of powders.
“Efficiency” is only important to the degree that “efficiency” is the goal. Other factors being equal, you can’t beat case capacity if higher velocity is the goal. I own more rifles than most (but still less than many others) and have yet to select one based primarily on “efficiency” – it has simply been one of several considerations and never the most important. If “modern” cartridge designers are stuck on “efficiency” first and foremost, a new .30 caliber cartridge would be much smaller than the .308 Win. In terms of fps/grain of powder, my .300 Blackout beats my .308 Win rifles by a wide margin.
Coyote Hunter - NRA Patriot Life, NRA Whittington Center Life, GOA, DAD - and I VOTE!
No, I'm not a Ruger bigot - just an unabashed fan of their revolvers, M77's and #1's.
