What was the technical reason for going from 30-03 to 30-06?

[KeithNyst]

The standard bullet for the 30-03 was a 220gr round nose. From what I've read, the driving force behind the 30-06 was the desire to use a lighter, spitzer profile bullet. My understandig is the the 30-03 case is essentially identical to the 30-06, except the 30-06 neck is 0.070" shorter.

Was there a technical reason why the 30-03 case would not work with a lighter spitzer bullet?

[raymeketa]

A no-brainer. Nothing complicated about it. The long neck was not needed to hold the shorter 150 grain M1906 bullet.

[KeithNyst]

I clearly agree the longer neck was not needed for a 150gr bullet ... but wouldn't a 150gr spitzer profile have seated in a 30-03 casing and worked in it as well? And there must have been considerable cost to transition tooling to 30-06 and retrofit all the 30-03s that had been made to 30-06; I'm thinking (perhaps way to hard :-)) that there may have been more to the decision. Maybe if a 150gr spitzer-profile bullet was seated in 30-03 casing and then chambered, it sat too far of the lands and had too much runup, which would have resulted in poor performance.

[raymeketa]

A 150 grain spitzer bullet certainly could have used in the '03 case with it's long neck. But, the question, as I understood it, was why was the neck shortened. That was done simply because it was not needed.

Yes, bullet jump and lessened accuracy was a consideration, but that could have been accomodated by simply changing the profile and ogive of the bullet slightly and by shallower seating. The decision to stay with the 7 ogive bullet and shorten the chamber (bullet seat), was the correct one, IMHO.

Since when has cost been a factor in most military decisions?

[Shooter5]

Since when has cost been a factor in most military decisions?

Well, in small arms procurement; all too often! Brits and US coulda/shoulda/woulda went to 6 or 7mm caliber before WW2 except service chiefs nixed that due to stockpiles of 303 and 30 cal. Still happens today. The Germans had similar issues with stockpiles of 7.9 influencing decisions. My decision: put all that ammo (303/30/7.9) into link and build ALOT more LMGs and build your squads around two per (Oh wait, the Germans DID do that!; and inflicted higher casualty rates per unit in comparison), and then build the lighter caliber assault rifle for the rest of the squad for fire and maneuver (Oh wait, the Germans did that, too! And the Soviets copied the ideas a al AK-47).

[raymeketa]

Both the 276 Pedersen and 276 Garand rifles passed most of the tests and were recommended for adoption when the caliber was vetoed very high up in the chain of command (Gen MacArthur). The last Cal .30 M1906 ammunition was made in 1921 and there were no huge stockpiles of the Cal .30 M1 ammunition, and the Cal .30 M2 cartridge was still several years away, so that was not a factor in the decision to retain the service cartridge.

In the early 1950s many Ordnance officers recommended the adoption of the 280 (7mm) caliber in the new short case and it was only because of a veto by the big brass that it did not happen. There was no stockpile of the 7.62MM NATO ammunition because it didn't exist at the time. The British actually adopted the 280 cartridge and EM2 rifle but that decision was overruled by none other than Churchill.

The .30 remained the primary infantry rifle caliber for more than 65 years because it was the favorite of the old school Ordnance officers, not because of any economics. Even the 5.56 x 45 was opposed by the old Ordnance officers and it was only adopted because of insistence by the USAAF and the circumstances of the VN war.

JMHO

Ray

[KeithNyst]

Regardless of reason for why the 30-03 morphed to the 30-06, the 30-06 is my all time favorite cartridge.

[Shooter5]

Both the 276 Pedersen and 276 Garand rifles passed most of the tests and were recommended for adoption when the caliber was vetoed very high up in the chain of command (Gen MacArthur). The last Cal .30 M1906 ammunition was made in 1921 and there were no huge stockpiles of the Cal .30 M1 ammunition, and the Cal .30 M2 cartridge was still several years away, so that was not a factor in the decision to retain the service cartridge.

In the early 1950s many Ordnance officers recommended the adoption of the 280 (7mm) caliber in the new short case and it was only because of a veto by the big brass that it did not happen. There was no stockpile of the 7.62MM NATO ammunition because it didn't exist at the time. The British actually adopted the 280 cartridge and EM2 rifle but that decision was overruled by none other than Churchill.

The .30 remained the primary infantry rifle caliber for more than 65 years because it was the favorite of the old school Ordnance officers, not because of any economics. Even the 5.56 x 45 was opposed by the old Ordnance officers and it was only adopted because of insistence by the USAAF and the circumstances of the VN war.

JMHO

Ray

Thanks. Even though CRS is kicking in, IIRC the figures for war stockpiles of ammo both pre/post WW2 for the US have been published and it was a fairly large amount. Obviously more in 1945 for 30 cal only. We have a similar situation today; there is every reason to adopt both a new/better rifle caliber as well as a general purpose LMG round…but it aint gonna happen.

[raymeketa]

After WW I there was a large stockpile of the Cal .30 M1906 ammunition on hand which was one of the reasons it was not made after 1919 except for a couple of small lots in 1920 and 21. In 1926 the first of the Cal .30 M1 was made but it was seldom issued until the stockpile of M1906 was finally used up in 1937. That was the year the first of the M2 was manufactured so most of the M1 was not used, except in MGs. After WW II, of course, there was a huge amount of all types of ammunition in storage. Some of it is still there.

But, the point I was trying to make was that the decisions to stay with the 30 caliber, in the 1920s, 30s, and 50s was not influenced by economics.

Ray

[Cosine26]

30-03 vs 30-06
It is my understanding that with the 150 grain M1906 bullet loaded into the 30-03 case, the space between the ogive of the bullet and the rifling was deemed to be to great and it was felt that the ‘jump’ would cause accuracy problems. The solution was to set the M1903 barrel back two threads, which would correct the space problem (I thought that this distance was called ‘lede’ but cannot confirm it.) When the barrel was set back, the 30-03 case neck was too long; therefore the case was shortened to accommodate the new chamber. This is discussed briefly in HATCHERS NOTEBOOK.
While it may be true that we did not have a great stock pile of 30-06 ammunition when the .276 was considered for the M1, we did have a large number of 30 caliber infantry weapons; i.e. the BAR, and several machineguns. Having a .276 rifle requiring .276 ammo, and a BAR or MG requiring .30 caliber ammo would have created a logistics problem. The War Department did not have the budget to replace all of these infantry weapons and did not wish to introduce the logistics problem. There were tradeoffs such as remaining ammo supply, capability to produce 30 caliber ammo by both government activities and civilian industries. Civilian industries could convert to producing 30M1 ammo or 30M2 ammo much more quickly than developing the capability to produce .276 caliber ammo. The 276 was a new and different round about which very little information was compiled and would probably entail a development program to produce satisfactory ammo.
In addition, After the decision to abandon the 276, several experimenters built bolt guns in 276 and using the surplus ammo found it to be not too accurate. That coupled with the lack of suitable cases, primers and powder caused the intrepid experimenters to drop the round. This was documented in several of the early AMERICAN RIFGLEMAN magazines.
Just an observation.

[PhillipM]

If logistics was such an issue why did they invent the .30 carbine?

[RCS]

another selection for the M1 carbine

Maybe, they should have just used the old 35 WSL instead of development of the old 32 WSL into the 30 M1 carbine cartridge

photos show the 35 WSL with a 351 dia bullet at 150 grs, it is in a carbine magazine too.
you would not have the velocity of the 30 cal 110 gr bullet - but you would think that a 35 cal bullet at 150/160 grs would be a better choice ?

[Maury Krupp]

When the order to stop work on the .276 M1 Rifle was issued the M1 Carbine, the mechanization of the Army, the motorization of its logistics system, and the german's game-changing tactics of 1939-40 were all still nearly a decade away. The country was in the middle of The Great Depression too.

The idea to introduce a completely new cartridge for a single weapon in the Army's inventory was a non-starter for anyone who saw The Big Picture as it was in 1932. Especially when that cartridge was of questionable and certainly unproven combat effectiveness.

Maury

[KeithNyst]

30-03 vs 30-06
It is my understanding that with the 150 grain M1906 bullet loaded into the 30-03 case, the space between the ogive of the bullet and the rifling was deemed to be to great and it was felt that the ‘jump’ would cause accuracy problems. The solution was to set the M1903 barrel back two threads, which would correct the space problem (I thought that this distance was called ‘lede’ but cannot confirm it.) When the barrel was set back, the 30-03 case neck was too long; therefore the case was shortened to accommodate the new chamber. This is discussed briefly in HATCHERS NOTEBOOK.
.

Thanks Cosine26. That is exactly the technical feedback I was looking for. Odd isn't it ... based on your info, the 30-06, one of the best cartridges ever, came about due to a practical, mechanical modification of the M1903 30-03 so that it could fire 150gr spitzers accurately ... not a "from a ground up" new cartridge design whatsoever.

[John Beard]

Seasons' Greetings!

The decision to shorten the case, adopt the 150-grain spitzer bullet, shorten the barrel, and re-chamber the rifles was actually a single consolidated decision based on testing and evaluation, not a series of separate decisions. It didn't cost any more to optimize the cartridge than to optimize the rifle to shoot it. So Ordnance reasoned that it was cost-effective to do both at the same time.

The argument that the barrels were shortened and re-chambered to restore accuracy doesn't appear to "hold water." A far more compelling argument is that the barrels were shortened and re-chambered to reduce gas blow-by.

Hope this helps. Happy New Year!

J.B.