Yesterday's Weapons Forums

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gschwertley
Concept Behind the Design of the 8x56R
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I have been thinking about the philosophy behind the 8x56R design. As a reloader when I look at the muzzle velocity compared to 8x57, it is seen that the x56 is less for the same given propellant and amount. So, we have to wonder why the Austrians and Hungarians would go for this in 1930 when more efficient cartridge designs were available. After all, the Austrians already had a more efficient cartridge in mind around the beginning of WW1 (7x57mm) but shelved the idea for the duration (and forever). True, the x56 was an improvement over the x50 design and the Holland and Holland-like case design was in vogue when this was being developed. BUT: I think that the 8x50R chamber shape may have dictated the design more than anything else. By boring the chamber out in the existing barrels, they could get a bump in muzzle velocity on the cheap without down-right rebarreling, as was done with the M95M and M95/24. Well, it's just a theory, but if it makes any sense, it would explain a lot.

junkbug
gschwertley;
I agree the Austrians and Hungarians were trying to improve their infantry weapons on the cheap.

The larger cartridge casing prevented it from being used in older, weaker M-88 rifles.

My belief is that the improvement was more driven by heavy machinegun performance, rather than rifle performance. 250fps, and a more aerodynamic bullet would noticeably improve very long range machinegun performance, especially in the light of First World War experience. It really does very little to the practical effectiveness of even a long rifle, since the rifle's sights are really the limiting factor, not the cartridge. I'm sure even the 8x50R is lethal far beyond most men's ability to hit with it, even using a long rifle.

It is interesting to note that most carbines and rifles have very generous chambers and throats. This would reduce pressure of the hot 8x56R load, in the carbine/rifle, while the machinegun may have had tighter tolerances, since it was stronger, and could make real use out of small performance gains.

Also, the Mannlichers could be loaded with old stocks of 8x50R and function just fine.

The point of the 8x56R "S" conversions of the Mannlicher seem, to me, to ad to its versatility, and make it compatible with an upgraded machinegun.

gschwertley
Well, Junkbug, you bring up some interesting points that are cause for more reflection.

The change over to spitzer bullets began long before the experiences gained from MG use in WW1. for example, 1906 in the US, and about the same time in Germany. The aerodynamic superiority of the design was recognized as applies to rifles.

I'm not sure that the Europeans thought of the rifle sights as limiting, since we see so many graduated to "2,000" although as a practical matter, I certainly agree with you.

It is true from what I know that the chambers in the 8x56R's are "biggish" but sometimes they are also generous in semi- and fully-automatic weapons as well to accommodate the rate of fire.

There is always the trend in military thinking to "keep up with the Joneses" with respect to technical developments. A gain of 200-250 fps in an infantry rifle and being able to do it on the cheap would be more temptation than military managers in a beaten-down country could resist. After all, there were a whole lot more rifles than MG to be converted. You mention that retention of the 8x50R would have been just as lethal in practical terms as the 8x56R. That's not how the military managers mind works! They have to have keep up to speed with their neighbors. Citing the French as an example, the 8mm Lebel also could have been retained during this time, but they chose to adopt "something new" in the 7.5x54. Back to the 8x56R, for the Austrians at that time, it was the best of both worlds, new and cheap.

The general trend in MG development during that time was away from rimmed cartridges and into rimless. Rimless cartridges just tend to work better in mechanisms; rifle, MG or whatever. The only rimmed cartridges used now around the world are designed for revolvers, and the 7.62x564R which is an anachronism that has hung around probably because of sheer numbers and wide distribution.

The Austrian 07/12 ("Schwarzlose") MG was also originally chambered for the 8x50R round. This machine was rather unique for a MG in that it operated on the simple delayed blowback principle, but I don't think this design feature figured into caliber conversion. The Czechs (and some other countries) when converting these to a more modern cartridge, chose 8x57mm (7.92x57mm), which was also in consonance with the caliber of their service rifles. The Czechs committed to spending the money for a more thoroughly modern rifle cartridge and their MG followed along in compliance. If the Austrians really wanted a hotter MG cartridge based on WW1 experience, they could have done with their MG's as the Czechs did instead of settle for less muzzle velocity with the 8x56R. I still think it was all about saving money for the Austrians.

Since you brought up chamber design, the Schwarzlose had a built-in oiler that lubricated each cartridge just before it entered the chamber. This was necessary due to the delayed blow-back design of the action. With this type of action, the extraction process wants to start while the propellant gasses are still expanding the case walls against the chamber. This makes extraction difficult, hence the lubrication system. You would think that with this situation, a tighter rather than a more generous chamber size would be disadvantageous. (This is just the opposite of shooting many other types of weapons, where you want a dry chamber to get good gas sealing.) It's only a guess, but this may explain, at least in part, just why 8x56R rifle chambers are generous. The Austrians may have established a standard chamber size during conversion based on the requirements for the MG. Having such a standard would save them from having two sizes of chamber reamers. Even though the MG was by far the lesser weapon in number, it may have set the common denominator for chamber size. Just like with shoes, a little larger is better than a little smaller. More likely the chamber size in the rifle is due to the problems inherent in the design of the straight-pull action, which lacks the extraction leverage of a turn-bolt.

The Model 88 series Steyr rifle could have been up-graded to take the 8x56R, just like many of the German Model 1888 Commission rifles were. This would have required re-barreling (like many of the German 1888's) and this would have cost more money. I speculate that beyond this cost, the size of both the 1930 Austrian and Hungarian armies was fairly small, certainly nothing like the numbers fielded in WW1, and they had more than enough M95 weapons on hand for cheaper conversion.