A 6.8mm caliber M16?

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http://en.wikipedia.org/wiki/6.8_mm_Remington_SPC
The 6.8 mm Remington SPC was designed to perform better in short barreled CQB rifles after diminished performance from the 5.56 NATO when the AR15 was changed from the rifle configuration to the current M4 carbine. The 6.8 SPC delivers 44% greater energy than the 5.56 mm NATO (M4 configuration) at 100–300 metres (330–980 ft). The 6.8mm SPC is not the ballistic equal of the 7.62x51mm NATO cartridge; however, it has less recoil, is more controllable in rapid fire, and lighter, allowing operators to carry more ammunition than would otherwise be possible with the larger caliber round. The 6.8 mm generates around 1,759 ft·lbf (2,385 J) of muzzle energy with a 115-grain (7.5 g) bullet. In comparison, the 5.56x45mm round (which the 6.8 is designed to replace) generates around 1,325 ft·lbf (1,796 J) with a 62-grain (4.0 g) bullet, giving the 6.8mm a terminal ballistic advantage over the 5.56mm of 434 ft·lbf (588 J).
In recent developments (the period 2004-2008) the performance of the 6.8 SPC has been increased by approximately 200 ft/s (61 m/s) by the work of one ammo manufacturer and a few custom rifle builders using the correct chamber and barrel specifications.

One of major complaints about the M16 is that its light bullet doesn't take down targets quickly and often requires multiple hits before putting a person down. Initially it was thought that the hypersonic bullets would create terrible wounds through tumbling, which would drop the target, but though the wounds often are quite bad, the target ends up with a mortal wound but and keep fighting and can kill the M16's wielder.

So what if instead of going the opposite direction of the M14, Stoner decides on an intermediate cartridge like 6.8mm? There were several of examples used by bolt action weapons, but they'd likely need to develop a new round for the weapon. Would it make the American rifles more competitive with AK47?
 
There was a cartridge very much like the 6.8 mm in the late 40s, .280 British. If the M14 had been chambered with this cartridge instead of the more powerful but less manageable 7.62 x 51 mm the problematic M16 could have been avoided.
 
There was a cartridge very much like the 6.8 mm in the late 40s, .280 British. If the M14 had been chambered with this cartridge instead of the more powerful but less manageable 7.62 x 51 mm the problematic M16 could have been avoided.

That wouldn't butterfly the M14's other problems like production dificulties and being longer and heavier than the AR10.
 
That wouldn't butterfly the M14's other problems like production dificulties and being longer and heavier than the AR10.

I think that in the 1950s the FN FAL in .280 was the best available option. The key problem would be getting the US military to go this far after being forced the take the .280. The less I say about the AR platform the better, I'm not a fan.
 
I think that in the 1950s the FN FAL in .280 was the best available option. The key problem would be getting the US military to go this far after being forced the take the .280. The less I say about the AR platform the better, I'm not a fan.

What's wrong with it?

AFAIK the only inbuilt problem with the AR is the direct gas impingement system is somewhat more prone to fouling than designs with a piston.
 
Isn't 6.8mm the diameter of the round and not the caliber?

It means more or less the same thing. Hopefully without boring you with interior ballistics, totally inside baseball. The bullet diameter and rifle caliber are different measurements, the bullet diameter being slightly greater then rifle bore. (Example .308 win. bullet diameter .308", rifle bore .300"=.30 caliber)

Why I dislike the AR. Three reasons, aluminum receiver, direct impingement and it remains the only rifle type where I needed to take it to a gunsmith just to clear a jam. :mad:
 
6.8 SPC is not as good as 6.5 Grendel. That would be a good round. Staying with the FN would have been a great idea. Honestly the .280 was a good cartridge, but I like the Grendel more. As well there is a 6mm round that can be used in a 5.56 chamber. http://www.chuckhawks.com/6mm_military_cartridge.htm

Also, the M-16 is a bad rifle because of the direct gas impingement. It is fairly accurate, has a moderate weight, and in general a good weapon. The German redesign of the Ar platform into an HK-416 is a great improvement. With its testing, the 10 inch carbine version is as accurate as the M-16 14 inch barrel on the range at over 300m. As well the HK is durable as hell. They drenched it in mud, water, and fired 200 rounds straight, then the guy cracked it open and pulled the bolt out. For those of you who do not know, firing that many rounds automatically with the M-16 then pulling the bolt out with bare hands, is a fast track to some good burns. The one main issue I have with the M-16 is cost. For us in the Canadian Military the C-7 is our M-16, just a different name. Without the Elcan Scope, or new Eo-tach sights, the weapon with 14 inch barrel is 3500$, which is ludicrous. A civilian, full-automatic version of the HK-416 is 2100$ with the aforementioned 10 inch barrel. For Canada this is what I would want, however America could do well with the same. Also Most of the time, I think we should just switch to bolt action sniper rifles, with KRISS Vectors as side arms. Bolt actions are extremely accurate, easy to service, and take a damn long time to wear down. You have the KRISS for trench clearing, urban ops, and close in Forest/Jungle.
 
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Interestingly, the G36's gas system (mostly the same as the one in the HK416) was based on the AR-18, itself based on another Armalite design by Eugene Stoner in the late 50s. Having what basically amounts to a primitive HK416 chambered in .280 British or equivalent by 1960 isn't impossible at all.

Of course, The US army could've gone with the .276 Pedersen in the 1930s, but that might be stretching things.
 
Interestingly, the G36's gas system (mostly the same as the one in the HK416) was based on the AR-18, itself based on another Armalite design by Eugene Stoner in the late 50s. Having what basically amounts to a primitive HK416 chambered in .280 British or equivalent by 1960 isn't impossible at all.

Of course, The US army could've gone with the .276 Pedersen in the 1930s, but that might be stretching things.

Yes, I could see that. It would be interesting to see a rifle like that. Originally though, I am an FN FAL fanboy, as they had fully auto versions. It was a durable rifle, and could have been chambered in .280
 
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