[Criminal Number 18F]

The real question will be what comes of the proposed 6,8mm ammunition developments

That is being pushed hardest by the raggediest-ass gang of phonies and wannabees I have ever seen... led by some guy who shouts about his rank, mumbles about naval special warfare, and when you actually take a hard look at him, turns out to be a dentist. What a fraud.

Way too much weapons development is being done by tinkering hobbyists and way to little by engineers. True or false: one reason the M4 had problems with bolt rebound, is that nobody did any analysis (not even a few envelope calculations, let alone FEA) on the system as revised?

When I bag on the process pushing the 6.8, I'm not saying an improved round wouldn't be a good idea, especially when the Army sacrificed the initial performance of the M193 round by stuffing the -16 with nasty, fouling ball powder instead of the stuff designed into the system. Which I think was a version of IMR that never made the commercial market, but definitely fouled less.

But the damn thing should have science and engineering behind it, not some phony without military, scientific or engineering credentials.

d.o.l.

Criminal Number 18F

[archy]

When I bag on the process pushing the 6.8, I'm not saying an improved round wouldn't be a good idea, especially when the Army sacrificed the initial performance of the M193 round by stuffing the -16 with nasty, fouling ball powder instead of the stuff designed into the system. Which I think was a version of IMR that never made the commercial market, but definitely fouled less.

Go ALL the way back, to the early 1950s, when the British developed the .280 EM-2 [actually a .276/7mm, usually described as the 7x44mm cartridge, or as the .280/30. Though the later version used the cartridge base and rim dimensions of the U.S. .30 cartridge in hopes that WWII-era manufacturing tooling and cartridge manufacturing machinery could be saved, an earlier versiou used a smaller diameter cartridge base and rim. And though the cartridge used a somewhat longer bullet [140 grain, IIRC] than most 5,56 ammunition, the slightly shorter case would allow the possibility of the use of the old EM-2 cartridge in weapons using a 45mm cartridge case: the 5,56x45mm M16 round and the Czech 7,62x45mm of the Vz52 carbine and Vz58 assault rifle in particular. That could allow ammunition development while the design and testing of such other possible platforms as the XM-8 or a *Super M4-plus* could be worked out.

Or the old EM-2 could be revived, using modern materials. The 700-800-yard effective range of that weapon would be nothing to sneeze at, nor should the possible effectiveness of it on soft body armor be overlooked. And it'd be a dandy in SAWs.

comparison table: British .280 caliber intermediate cartridge vs. most common modern military cartridges
ballistic data is estimated using Norma ballistic calculator and Sierra Bullets data on ballistic coefficients.

	5.56x45mm NATO	7x43mm EM-2	7.6x39mm M43	7.62x51mm NATO
bullet weight	4.01 g (62 gr)	9.08 g (140 gr)	7.9 g (122 gr)	9.72 g (150 gr)
bullet velocity, at muzzle	921 m/s	745 m/s	710 m/s	860 m/s
bullet velocity, at 300 yards (273 meters)	585 m/s	570 m/s	470 m/s	674 m/s
bullet velocity, at 550 yards (500 meters)	385 m/s	450 m/s	341 m/s	516 m/s
bullet energy, at muzzle	1700 J	2519 J	1991 J	3594 J
bullet energy, at 300 yards (273 meters)	686 J	1475 J	872 J	2207 J
bullet energy, at 550 yards (500 meters)	297 J	919 J	460 J	1294 J

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