Friday, November 30, 2012

.30-06: The Infantry Magnum

I already demonstrated elsewhere that the .30-06 set a suspect trend of low case taper in US military rifle cartridges.

Continuing my War On .30-06, I am also going to provide evidence that the .30-03 Springfield (the .30-06's close ancestor) was a massively overpowered cartridge for the period, and started a trend where cartridges became more powerful than necessary, higher pressure than they had been previously, and higher recoil than is desirable.

Thanks to the magic of Google, I've found powder charge figures for all of the above cartridges, which, coupled with rifle weight figures, gives me the ability to calculate recoil energies for each cartridge/rifle combination. They are listed below the muzzle energy data. Do note that the recoil figures are using rifle-length velocities and weapon weights (to give an idea of how manageable each rifle was), whereas the muzzle energy data is all using approximately 24" barrels (to show how powerful each cartridge was, all things being equal), which was considered carbine length at the time.

Without further ado, I present the .30-03 Springfield, and every major round nosed rifle cartridge in service at that time:

.303 British Mark II
13.9 g (215 grs) bullet on 2.01 g (31.0 grs) cordite at 600 m/s (1,970 ft/s)
2,510 J muzzle energy
15.7 J recoil energy

7.62x54mmR M1891
13.7 g (211 grs) bullet on 2.20 g (34.0 grs) pyroxiline at 615 m/s (2,020 ft/s)
2,610 J muzzle energy
16.7 J recoil energy

.30-40 Army M1894
14.3 g (220 grs) bullet on 2.59 g (40.0 grs) W. A. at 600 m/s (1,960 ft/s)
2,550 J muzzle energy
18.2 J recoil energy

7.9x57mm Patrone 88
14.7 g (227 grs) bullet on 2.55 g (39.3 grs) S-Pulver at 600 m/s (1,970 ft/s)
2,650 J muzzle energy
20.5 J recoil energy

8x50mmR Lebel Balle M
15.0 g (231 grs) bullet on 2.75 g (42.4 grs) Poudre BF at 580 m/s (1,900 ft/s)
2,520 J muzzle energy
19.4 J recoil energy

8x50mmR Mannlicher M.93
15.8 g (244 grs) bullet on 2.75 g (42.4 grs) M.92 at 600 m/s (1,970 ft/s)
2,840 J muzzle energy
25.1 J recoil energy

7x57mm Mauser Modelo 1893
11.2 g (173 grs) bullet on 2.40 g (37.0 grs) nitrocellulose at 670 m/s (2,200 ft/s)
2,520 J muzzle energy
16.0 J recoil energy

6x60mm Lee Navy M1895
8.75 g (135 grs) bullet on 2.14 g (33.0 grs) Rifleite at 730 m/s (2,380 ft/s)
2,310 J muzzle energy
12.2 J recoil energy

.30-03 Springfield M1903
14.3 g (220 grs) bullet on 2.92 g (45.0 grs) W. A. at 700 m/s (2,300 ft/s)
3,510 J muzzle energy
25.5 J recoil energy

That's right, the .30-03 has almost a third again as much muzzle energy and more than 20% more recoil energy than the third-most powerful round-nosed smokeless powder cartridge of the era.

This means that an army training on, say, .303 caliber rifles will have an easier time teaching marksmanship, will have lower re-acquisition times after each shot, and will experience less fatigue during shooting.

Given that during the interwar period and Second World War many nations switched from a softer-shooting rifle cartridge and a longer-ranged machine gun cartridge to issuing the machine gun cartridge for all purposes or switching from a less powerful cartridge to a more powerful one, and that the ubiquitous postwar 7.62x51 NATO was just as powerful as the .30-03 Springfield, I think it can be said that the .30-03 Springfield set off a trend of unnecessary recoil, muzzle energy, and high pressure.

The 8x50R Mannlicher is something of an outlier. It produces similar recoil to the .30-03 cartridge, but far less muzzle energy. Interestingly, it is also the only outlier found in my analysis of case taper in military cartridges. The Austro-Hungarian Empire was fraught with decay and corruption at this point in history, and so it is possible that the development of the 8x50R cartridge was beset by similar demons as could be found in the development of the .30-03 cartridge. It is also possible that Austro-Hungary and the United States were the only two countries that designed their rifle cartridges correctly, but this seems unlikely to me. It is worth noting that the 8x50R Mannlicher does not have greatly higher velocity or sectional density than cartridges such as .30-40 Army, .303 British, or 7.62x54R, but due to its larger caliber (.330") required a heavier bullet and more powder to propel it to speed. The .30-03, in contrast, is faster than its stablemates, by about 350 f/s.

4 comments:

  1. The 8mm Lebel Balle D was introduced in 1898, so 198grains at 2,400 fps for 3,364 J of energy is within spitting distance of the 30-03.

    The relative performance gap between the 7x57 and 30-40 US in the Spanish American War was the major impetus behind the development of the 30-03. To equal the ballistics of the slimmer round a bump in velocity was required. Was it smart? Not really, and that recoil issue would come back to haunt the 30-06 in WWII. The poor long distance machine gun results in WWI led to the development of the M1 Ball loading, which would be comparable to M72 match (except with cannelure and crimp), but the excessive range fan and recoil pushed the National Guard units to request M2 ball, which the Army then standardized forgetting about the lessons for machine gun performance in the previous big war.

    Would have been smarter from the get go to adopt the 6.5x55 along with the Krag rifle. Logistically it uses less material per cartridge in every aspect save the primer, and recoil is greatly reduced.

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    1. Yes, the 8mm Lebel (and a couple others that existed before) come close to the performance of the .30-03, but what's remarkable about the Springfield cartridge is that it does so from a carbine length barrel.

      You and I both agree, I think that the .30-06 has, as a result of what was maybe a bit of an overreaction to 7mm Mauser (or maybe just the insistence on a .30 caliber bore), proven to be a bit more than is necessary not only for military use but for civilian use as well. This explains to me why most .30-06 rifles in use in the civilian market today are legacy deals, with the slightly weaker .308 Winchester taking its market share almost whole hog. It's reasonable to assume that the .308 Winchester achieved such success in large part because of its lower recoil, as it's difficult for me to imagine that a mere half inch overall length difference would so thoroughly convert sportsmen over to its side. But maybe something else was going on, who knows?

      Further evidence of .30-06 being too big is given by the development of the .276 Pedersen. By the mid twenties, it was pretty obvious that the .30-06 was "too much" cartridge.

      Cheers,
      -Nathaniel

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  2. .30-06 is by no means dead in new rifles.
    In an average gunstore in Sweden, .30-06 is by far the most common calibre in new rifles,
    with even break action rifles and combination guns using .30-06.
    .308 is today about as common as 9,3x62 and 6,5x55 about as common as .375 and larger bores.

    10 or 20 years ago, new .308's were more common,
    but since then the access of cheap 7,62x51 from the army has dried up,
    and we have seen a shift in hunting in the south from virtually no animals
    larger then 40 to 60 pound dears to seing 200 pound wild boars being more common
    for every year and a drastic increase in bear hunting in the north
    has led to hunters opting for larger calibers and higher sectional density.

    So if .30-06 is dead on the civilian market, then every caliber exept 12 gauge is also dead.

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    Replies
    1. I don't recall saying that .30-06 was dead. Certainly, it's a mainstay caliber for long-action guns. However, .308 rifles seem to be more common, at least where I'm from.

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