sillygoose
Well-known member
What if the militaries of Europe realize that a two caliber standard for infantry arms is the right way to go before WW1 and they work on developing an optimal infantry caliber for light weapons?
The French developed something like this in the early 1900s:
Theirs were very hot though and would have been barrel burners, hence the final toned down 7x57mm cartridge for the Munier rifle. But what if they realized the 6mm caliber was the way to go for most infantry roles and they settled on that while making their 8mm cartridge into an HMG caliber? Let's say they do that in 1903-5 when that was the favored caliber.
The rest of Europe could follow quickly, as the British also ended up developing a 7mm Enfield cartridge, but delayed like the French so that it never saw use in WW1 in any significant capacity.
The virtues is a cartridge that could still reach out to 1000m, use a shortened existing cartridge case for most countries (provided also made rimless), be quite light recoil, and would allow for nearly double the ammo per same amount of weight. Plus less material means more savings in general to make.
Leaving the larger calibers for HMG units wouldn't be a significant problem logistically given how HMGs were treated in 1914 as effectively artillery pieces and that could also allow for them to be made more powerful for longer range and AP work, much like how the Swedes used 6.5mm general purpose cartridges, but a powerful 8mm one for HMGs:
Also the lighter cartridge means rifles/carbines and LMGs/auto-rifles could be made lighter as well as one day evolve into SLR/battle rifle cartridges with little to no modification.
How might this POD impact the battlefield in WW1? Recoil would be close to half that of the OTL cartridges, about twice as many rounds could be carried, heat buildup would be about half as well, accuracy would be higher, barrels could be shorter, less materials could be used, and SLRs would be much easier to make (same with LMGs/auto-rifles) not to mention cheaper. Also keep in mind until 1916 bullets inflicted more casualties than artillery in WW1.
Might weapons like the Lewis Gun and Chauchat (or Madsen) have been lighter and more reliable/useful with a cartridge like this? The Chauchat had a problem of overheating with the 8mm Lebel and even worse one with the .30-06. The Lewis gun had that expensive and overly complicated forced induction barrel shroud. Or would even a light belt-fed MG be viable with a fixed barrel like the RPD? Certainly the French had some interesting 6mm designs pre-war for an auto-rifle, effectively a pre-war BAR in 6mm:
Crist argued for the adoption of a 6mm rifle chambering as a replacement for the venerable 5.56×45mm NATO and 7.62×51mm NATO, calculating that such a loading would be near the weight and minimal recoil of the lightweight 5.56 while nearer the terminal performance of the heavier 7.62, thereby permitting a single caliber to serve in general-purpose machine guns, sniper rifles, and infantry carbines.[1][2]
Crist's specifications were that "6mm Optimum" ammunition achieve, with a 100 gr (6.5 g) bullet:
...of which he noted, "...even with a conservative estimate for the muzzle velocity of the 6mm Optimum cartridge, computed data for 1200-meter velocity, flight-time, wind-deflection, and trajectory height are all greatly superior to both 5.56 and 7.62 NATO rounds."[1]
- Muzzle velocity: 880 m/s (2,900 ft/s)
- Velocity at 1200 m: 350 m/s (1,149 ft/s) (slightly over the speed of sound)
- Muzzle energy: 2,531 J (1,867 ft⋅lbf)
- Energy at 1200 m: 397 J (293 ft⋅lbf)
- Flight-time to 1200 m: 2.21 seconds
- Deflection at 1200 m: 3.8 m (151 in) in 4.5 m/s (10 mph) wind speed
- Maximum trajectory height: 6.2 m (244 in)
The French developed something like this in the early 1900s:
Meunier rifle - Wikipedia
en.wikipedia.org
Cartridge development[edit]
The Section Technique de l'Artillerie (STA) developed various rimless high performance cartridges from 1890 to 1912. Among these cartridges, some were retained:
- 6×58 Meunier 1897
- 6×60 ENT, 1900
- 6.5×60 CAP 1905
- 6.5×61 STA 1910
- 6.5×55.5 Berthier 1910
- 7×59 STA 1912
- 7×57 Meunier 1912
Theirs were very hot though and would have been barrel burners, hence the final toned down 7x57mm cartridge for the Munier rifle. But what if they realized the 6mm caliber was the way to go for most infantry roles and they settled on that while making their 8mm cartridge into an HMG caliber? Let's say they do that in 1903-5 when that was the favored caliber.
The rest of Europe could follow quickly, as the British also ended up developing a 7mm Enfield cartridge, but delayed like the French so that it never saw use in WW1 in any significant capacity.
The virtues is a cartridge that could still reach out to 1000m, use a shortened existing cartridge case for most countries (provided also made rimless), be quite light recoil, and would allow for nearly double the ammo per same amount of weight. Plus less material means more savings in general to make.
Leaving the larger calibers for HMG units wouldn't be a significant problem logistically given how HMGs were treated in 1914 as effectively artillery pieces and that could also allow for them to be made more powerful for longer range and AP work, much like how the Swedes used 6.5mm general purpose cartridges, but a powerful 8mm one for HMGs:
Also the lighter cartridge means rifles/carbines and LMGs/auto-rifles could be made lighter as well as one day evolve into SLR/battle rifle cartridges with little to no modification.
How might this POD impact the battlefield in WW1? Recoil would be close to half that of the OTL cartridges, about twice as many rounds could be carried, heat buildup would be about half as well, accuracy would be higher, barrels could be shorter, less materials could be used, and SLRs would be much easier to make (same with LMGs/auto-rifles) not to mention cheaper. Also keep in mind until 1916 bullets inflicted more casualties than artillery in WW1.
Might weapons like the Lewis Gun and Chauchat (or Madsen) have been lighter and more reliable/useful with a cartridge like this? The Chauchat had a problem of overheating with the 8mm Lebel and even worse one with the .30-06. The Lewis gun had that expensive and overly complicated forced induction barrel shroud. Or would even a light belt-fed MG be viable with a fixed barrel like the RPD? Certainly the French had some interesting 6mm designs pre-war for an auto-rifle, effectively a pre-war BAR in 6mm: