U.S.A powders and the 7,62x51NATO development


#1

This is not a reloading thread; it is about the 7,62x51/.308 Win. development.

I have read an article about the .308 Win vs .30-06 Spr…
The author writes that the 7,62x51/.308 Win. could not be created before because the powders in use in U.S.A. were not good enough for developing a ballistic close enough to the .30-06 Spr. before 1950.
My question:
Was rifle powders much better in 1958 than in 1906 for reloading the 7,62x51NATO to the standard performance?

Hope my English is good enough.

Thanks
Martin


#2

Martin

Smokless rifle powders have been improved over the years since their initial development and continue to do so even today. Cartridge design naturally follows. There are high-intensity cartridges today, not much more than 1 inch long, that pack the same punch as a 2.5" cartridge did 70 years ago. Improved powders take much of the credit.

Powder suitability was just one factor that led the OD to begin investigation of a short Cal 30 cartridge in 1944. The powders used in the experimental cartridges were available before that time so saying that they were not good enough is not correct. The IMR (Improved Military Rifle) powders such as 3031, 4320, and 4895 were developed in the mid 1930s. I’d say that politics and WWII were probably the biggest reasons for delaying the development of a new infantry standard until the late 1940s.

JMHO

Ray


#3

Thanks Ron.

According to this author, the .308 Win. could not be posible becuase the inexistence on USA powders capables of developing its ballistic (as a side bar he sais that Germany had those powders).
Even thou there was improvementes in smokless powders, how much better was IMR comparing to 1906 powders, not much IMHO.
I belive this is not true because any powder that works in the .270 Win. (1925) is good for the .308 Win…
Also, ithe .300 Savage a cartridge almos identical to the .308 Win. but loaded to a lower pressure have almost the same ballistic.
What powder was used to load the .30-06 Spr. at 1910?
Thanks
Martin


#4

American Powders go through three (some say Four) distinct phases.
The first phase goes from the development of Smokeless Powders in the USA in the 1890s, and the very fast , high temperature Powders used in the .30/40 Krag, the 6mm Lee Navy, and then the early .30/06. Some of these Powders were single base, others double base; no flame retardants were used, and the shapes of the individual grains varied.

Just before WW I, Dupont developed the MR ( Military Rifle) type of Tubular Powders, single based, to control better the burning rates, by surface area control ( outside, inside, and length). They also tried different coatings of the Powders, ( Powders with “1/2” added to their Number…WW I MRs had numbers in the 10-18 range.

Then in the 1920s, with improved chemistry, and appreciation of the destructive (to gun barrels) nature of a lot of then current Powders, Dupont, fresh from acquiring a lot of German Information, developed the IMR series of Powders, in the 11xx series, specifically for the new, M1 cartridge ( 173 grain Boattailed, for Long range and MG shooting.)
The IMR series featured Tubular design, flame retardand coatings, and more regular grain size. The Range of Civilian Powders developed was to cater for both the Bulk loading needs of the Ammunition companies, as well as the reloading needs of the growing number of DIY shooters, in the 1920s ans 30s.

BY 1940, such powders as IMR 3031, and 4895 has been developed and fully tested, both Militarily and commercially.The introduction of the M1 garand rifle hastened the development of 4895, as the cartridge for the semi-auto reverted to a 152 grain projectile , similar to the original M1906 cartridge. The requirements of gas operation also mandated a more conrollable burning Powder.
Other, heavier Powders had been made for .50 CAL (#5010 ,)& #4831 for 20mm). Whilst some early batches of .303 British for Britain had been made with #3031 ( it reflected Cordite in its burning efficiency), when the Canadians started loading Boxer primed .303 ( DI headstamp) they used for the most part, a Bulk-supply Powder called IMR 4740 ( never available as a commercial canister Powder, but long used in Australia after the war as a “repacked surplus” powder, for the same range of cartridges as both 3031 and 4895.)

BY the end of WW II, Olin’s patent of “Fluid Manufacture” of Powder ( especially double based) “Ball Powder” gave an alternative to the traditional “Tubular grain” powders then available. Somehow the US had never entertained the use of German style “Flake” Powder ( or “Lamellar Powder” to give it its correct technical name.)

These WW II developments allowed the development of the shorter “T65” .30 cases, and subsequent 7,62 Nato cartridge. The .30 Savage’s case was merely a trial vehicle along the way, in its case size ( 47 mm)…a whole range of case lengths were tried in the US, Britain and Belgium, untill the US eventually settled on 51mm, as the “ideal case”.

Nowadays, IMR Powders have come further, with the development of “Controlled Porosity” of the Nitrocellulose matrix of the grain structure.
This improves Burning rates and flame temperatures. A development of the former Australian Govt Explosives Factory at Mulwala ( set up by Dupont in 1942-3 ( now “ADI-Thales group” , Mulwala). The ADI :AR series of powders are now exported to both Military and sporting ammo factories the world over, and also sold under various “House brands” in the USA, under different names. Hodgdon Powder was a big customer, and ADI even developed a 4895 Clone in AR2206H ( or is it 2208H???) to replace the now extinct Milsurp H4895.

If the 6mm M1895 Lee had been a Post-WW II development, it would have benefitted from excellent , ballistically matched Powders…back in 1895, the early smokeless of the time, was still not suited for small calibre cartridges…
Too fast, too hot, and too unstable in storage.

Rifle Powders have come a long way since the 1890s.

regards,
Doc AV
AV Ballistics
Brisbane, Australia


#5

Martin

There is a world of difference between smokeless powders available in 1906 and those of 1945. I don’t think there is any way to compare those powders with the MR (Military Rifle) and IMR (Improved Military Rifle) powders. Arguing the differences would be pointless.

The first M1903 and M1906 cartridges were loaded, I believe, with the same nitroglycerine powders used in the 30-40 Krag until they were replaced around 1910 by straight nitrocellulose powders such as Pyro DG.

The first experimental cartridges leading to the development of the 7.62 x 51 were loaded with commercial 300 Savage cases. The powders were, as I said earlier, canister lots of 3031, 4895, 4320, powders that had been available for sporting cartridges in the mid 1930s. Spherical powders were used after 1948 or so, and in all the NATO cartridges, not because the stick powders were not suitable, but because ball powders are so much easier and cheaper to manufacture and to load.

Who is this “author” you refer to?

Ray


#6

DocAv, Ray,
Thank you very much for your answers.
That


#7

DocAV

You did a great summary of a very complicated subject. I’m sure most readers were glassy-eyed at the end but I appreciated your effort. And I learned a few things too.

Many cartridge collectors are missing an important aspect of the hobby when they ignore what’s inside those brass cases. I always try to get at least two examples of a cartridge so I can break one down to see what the powder looks like. There’s a lot of history in there, and usually a surprise or two.

Ray


#8

Not to debate because I think the powder was not the reason because the 7,62x51mm NATO was not developed before 1950.

Just found this on