30-06 design questions

[stubbicatt]

I'm not sure where to begin my search to find an answer, for what is to me, a particularly vexing aspect of the 30-06 cartridge design.

I understand it began life as the 30-03, same basic case with a heavier, round nose, bullet. There was a change in 06 to the present configuration, with a spitzer bullet. Yet there remains inside the case with a M2 ball load of 4895 or the equivalent, and a 150 grain bullet, a lot of airspace.

I find myself wondering why they designed a cartridge with so much unused powder capacity?

 

[PRD1]

Probably because...

the 1903 and 1906 loadings were originally dependent on the early smokeless powders, such as Whistler-Aspinwall (WA), which were less dense than later developments, and likely needed the additional space.
This turns out to be a serendipitous characteristic, which permits the .30-06 case to be loaded to deliver much better ballistics with any weight bullet, and take advantage of later, denser but slower-burning propellants.

PRD1 - mhb - Mike

 

[rcmodel]

They probably needed the case capacity with the longer 220 grain RN and smokeless powders of the day in the 30-03.

Then the change to the spitzer bullet was made 3 years later to keep up with the French and Germans.

And the original 30-03 Springfield's were modified by setting the barrels back and re-chambering them with the new chamber with a shorter case neck.

Too late to design a new rifle around the existing cartridge length at that late date.

And by then, Army Ordinance was starting to suspect the French were onto something again with a heavier Balle D boat-tail bullet weighing 198 grains.

It & the German heavy boat-tail spitzer had vastly longer range then our 150 flat-base bullet when used in machineguns. Like 50% more range.
And that wouldn't do if we ever had to fight them.
Which we did, twice.

I suspect they wanted to leave themselves enough case capacity to go with a heavier spitzer boat-tail bullet later on.
And by the 1920's they had, with the 174.5 grain M1 ball load.

And by then, it was too late, (or too early?) to re-design the 30-06 case into the .308 case, and have to start over designing new rifles and machineguns for the shorter case.

Because the dogs of war were straining at the leashes again by then.

rc

 

[Jim K]

That empty space was one of the reasons for the adoption of the 7.62 NATO, a more efficient case with comparable ballistics and considerable savings of brass, a critical material in war. (During WWII, Frankford Arsenal turned out 1.2 million rounds of .30 ammo - per day. Shortening the case 1/2 inch would save a lot of brass at that rate.)

Of course the reduction of cartridge size also meant less shipping space per round. less of a load for the GI, and a reduction of weapon size and weight.

Jim

 

[rcmodel]

All true of course.

But I don't think anyone thought of it that way between WWI and WWII, or for the next few years after.

The thinking at the time was, He who had the Biggest cartridge, Won the war.

It was only after WWII and the German 7.62 Kurz, that planner and dreamers thought we could even fight with a shorter less powerful cartridge.

Of course the schemers and plotters from the old school military still thought 'His had to be bigger then the next guys', or it didn't count!

That's how we got the 7.62 NATO & the M14 instead of an intermediate modern assault rifle & cartridge in a the 1950's.

But of course at the time, the cold war was in full bloom, long range battles in war in Europe was thought to be eminent.
And nobody had a clue we would be fighting in the jungles of Vietnam in a prolonged political war of attrition a few years later.

Had they?
The .308 NATO & 5.56 NATO might just as well have been the .280 NATO the British were lobbying for.

Or the .276 Pedersen the M1 Garand was almost chambered in had not the old brass hats lobbied for the 30-06 to be retained.

And we might be better for it in the sandbox today??

rc

 

[Jim K]

Probably the best thing we could have done c. 1957 would have been to just adopt the AK-47. But somehow I don't think that would have flown very well with Congress in the McCarthy era. (And they didn't even have Fox News or Rush Limbaugh!)

The retention of the .30-'06 in the 1930's made a lot of sense. With tiny military budgets (they almost fired Garand because his $2800 a year salary was too high) and a big stockpile of .30 ammo left over from WWI, changing to a new cartridge just didn't make sense. The Pedersen rifle could not handle .30-'06, where the Garand rifle had already proven it could. And that stockpile of WWI ammo got us through the first half year of WWII until the ammo plants could crank up.

Jim

 

[rcmodel]

+1

But getting back to the OP's question?

It's really a good thing that the old 30-06 had the excess case capacity it had back then.

Otherwise, it wouldn't be able to almost match the .300 H&H Magnum, and far exceed the .308 with heavier bullets and todays slower burning less dense super-powders.

It is what it is today in no small part by hunting performance that can't quite be equaled by the 'just right size' .308 case.

rc

 

[Jim K]

The military does not think like a hunter. The average hunter picks up a box of ammo at Pete's Gun Shop, puts ten cartridges in his hunting coat pocket, and is good for the season.

The military picks up a million rounds a day at the local ammunition plant, arranges for a few more freight trains of powder to be delivered, gets several trains to take the ammo to the docks, loads it onto ships, offloads it at the port of destination, trucks it to the front lines, etc, etc. And any not used has to be stored at considerable cost. And any issued to the troops has to be humped forward.

To the hunter, saving a few cents on ammo cost or an ounce or two on weight doesn't matter. To the Army, that savings is in millions of dollars and tons of shipping costs.

Jim