New 6.8x43mm Special Purpose Carbine

[virtualpender]

http://www4.aixgaming.com/opend/album18/troycqb_spc

Developed by Troy Industries at request of Crane NSWC. If anyone has any additional information, please post.

Thanks

[Ratamacue]

Talk about fugly.

[Minjin]

looks kinda like some plain M4 variant with an ARMS SIR on it or something. I don't like it personally.

[Minjin]

Double post (?!?!?!?!!?)

[virtualpender]

Yeah, just a boring, plain M4 variant in a new, just adopted 6.8x43mm round. Nothing special about that...

[Apogee]

I'm in agreement on this one. Haven't really heard much call for a 6.8 mm round. But i guess i can see how it would be useful in certain situation.

[Chops]

Anyone know the score on the 6.8?

Rgds

Chops

[96B]

Despite the fact that I dont know anything about this weapon, military weaponry isnt made to look cool, its made to kill. Just because something doesnt look sleak and futuristic like an HK doesnt mean that its not a good weapon.

[StarvingStudent47]

Why the call for a 6.8mm round? Does 5.56mm no longer have enough stopping power?

[Kitsune]

An HK is a good weapon though...

[Ratamacue]

Starving, it's pretty well known that 5.56mm NATO doesn't have the stopping power required in many situations to take down an enemy. While the wounds that the AR15 series creates tend to be pretty nasty, often times the rounds will just go straight through and leave a clean hole. That's why the SEALs still often use the M14, and, if you saw/read Black Hawk Down, DELTA Sniper Randy Shughart used the M14 has his rifle of choice.

Even 6.8mm probably won't be that powerful, and shortening the cartridge with an already heavier round will probably make it less accurate. I'm assuming they're beginning to put it through trials in the field now or something?

[virtualpender]

The 6.8mm round sounds impressive. 125 grain, .276 in. bullet with a muzzle velocity of 2750 fps. I believe the ballistic coefficient is .360 which would make it a straight shooting round.

Looks like a step in the right direction.

[96B]

HKs are definately awesome weapons I was simply saying that just because a weapon doesnt look futuristic or cool doesnt mean that its not effective.

Yea the 5.56's begin to tumble at longer distances and thats when they really tear you up, but at close range due to the high velocity and small size they just pass straight through. Im no weapons expert, but I remember reading somewhere that the original M16s being tested in Vietnam really tore up the oponents (blowing off limbs etc). It stated that there was some ratio of rifling twist that directly effected the lethality but the government chose to use another twist ratio for better accuracy over longer distances. Im not quite sure specifically the ratios or the scenarios but I read it in a magazine a couple weeks back.

Personally I think it would be awesome if the US and/or other countries were to come back out with the larger caliber for close combat and reserve the smaller ones for longer distance engagements if possible. You hear alot of Veterans referring to the M16 and the more modern assault rifles as feeling like toys compared to the heavy M14s and such.

[...]

Yeah, that's what the goverment should do, start making everything heavier.

[96B]

If you are attempting to be sarcastic or if you were serious, my point was bigger rounds have better stopping power with the exception of making other things heavier. It would be much better to have a slightly heavier rifle and be able to kill with far fewer rounds with much less risk to the soldier than to have a light weapon that isnt guaranteed to get the bad guy initially.

[Ratamacue]

Rifles that fire 7.62mm don't even necessarily have to be heavy. The M14 and FAL were only heavy weapons because they were designed to be able to fire fully-automatic, which thus made everything inside reinforced (many versions of both weapons were later limited to semi-auto, but retained reinforcement).

I *somewhat* agree with you on that point, semper. More powerful weapons would most likely lead to less ammunition used due to stopping power and increased accuracy. However, you still need decently light, full-auto weapons for CQB, which I don't think a 7.62mm weapon could provide.

In any case, the small-caliber revolution since Vietnam has basically taken over the government, so don't expect ammunition much more powerful than 6.8mm to be coming into use outside of MMGs/SPRs/sniper rifles.

[FallenAngel]

what about the SR25.....it's an M16 chambered for 7.62 Would THAT prove more acceptable? ;)

[Chops]

Hey Virtual

Been a while mate, where you been hiding? Good to have you back.

I'm intrigued by this 6.8 M4. Like you say, ballistically like a .270 which used to be my favourite hunting calibre many moons ago. Flat shooting and enough grunt to drop the bad guys; dependant on the round profiles, I think they might well be on to something.

Is it in use? I need more on this baby.

Rgds

Chops

[Chops]

Have you seen this daddy of an M14? Crane NSWC contract. Anybody seen one of these?

http://www.troyind.com/SOPMOD%20M-14.htm

Rgds

Chops

[virtualpender]

Chops - thanks for the welcome back. Work has kept me away.

Re: the 6.8mm. I don't have any info on whether or not the round has been fielded yet.

Re: the M14 SOPMOD. That is a really outstanding setup. Troy displayed that at the SHOT Show in Orlando and I've read that everyone who saw it was impressed. I believe there is a thread about it over on ar15.com

[GazB]

"Yea the 5.56's begin to tumble at longer distances and thats when they really tear you up, but at close range due to the high velocity and small size they just pass straight through. "

Not true.

The rifling in the barrel is what stabilises the bullet. Every bullet, unless it is designed to be unstable, will maintain its stability till it hits something. Most bullets, including .308 calibres will be so stabile that even if it hits you it will tend to travel point forward for about 10cm, unless it hist bone or a belt buckle or something. After it has travelled about 10cm through flesh it will turn over and travel with its point facing backwards. By this stage it has usually left a human body. What makes the .223 remington round so lethal is that it has a clanure half way down it. A clanure is a series of dimples in a cirular pattern around the bullet that the case is crimped into to stop the bullet being pushe deeper into the case during handling or loading. This line of square dimples is a line of weakness. After travelling though the human body for 10cm as it tumbles and is moving though the body and varying angles from 0 to 180 degrees the bending forces on the bullet increase till at 90 degree they peak.
From a 20 inch barrel (ie standard M16) out to about 200-250m the velocity is high enough that the bending forces break the bullet at 90 degrees which results in multiple fragments and a large wound channel.
For a 16 inch barrel the velocity required to reliably break the bullet is very close to the muzzle, so unless a bone or some other hard item is hit it just causes a clean wound.

The Soviet M1974 round is designed to tumble on impact and is not range or velocity dependant.

It shares the same problems as the .223 round in that it is very light and can be deflected by almost anything including branches.

I have some line drawings of test results by Dr. Flacker (who specialises in wound ballistics) if you are interested in a comparison between some common military rounds.

[nathan_w_l]

Yep gazb hit the nail right on the head. one very interesting thing I saw the other day was a new 100 grain honady bullet that was being developed specifically for military and was designed specifically as a frangible round would make some very, very large holes in ballistic gelatin.

I heard the argument once that the M-16A4, M-4, M-249, and M-24 should all be switched over to either a 6.8mm or 6.5mm round therefore simplifying the log process.The theory was that a 6.5mm round would be the ideal compromise between all the formentioned weapons systems. whether or not this theory holds water I don't know because I haven't seen it tested so I have no facts either way, but that was the theory anyway.

[GazB]

One of the nicest rifles in 308 that i never got to fire :cry: was the AR-10.

It was very much like an AR-15 (that became the M16) but you could tell by the fact that it looked like it was made of aluminium and of course the 20 round 308 magazine.
Just arrived too late to save the 308 as the infantry round.

Nathan...

'I heard the argument once that the M-16A4, M-4, M-249, and M-24 should all be switched over to either a 6.8mm or 6.5mm '

Funny you say that, just because the Soviets were planning to do that just before they collapsed in the early 90s. In their case it was originally a 6.5 x 54mm round, though later they developed a 6.5 x 49mm round with the same velocity.
Performance was 120 grain bullet at 1200m/s, which is quite impressive, though it might wear out barrels. I'd heard they were also looking at caseless rounds with compacted propellents that halved the length of the round and greatly reduced weight due to no brass, but the collapse of the SU and no money for reequipping the arsenals with tooling to make the new weapons and ammo it wasn't going to happen.
Post 1990 information about the smaller projectiles would perhaps suggest that a heavier round might be more desirable anyway.
(There were new weapons designed but they still looked similar to the older models... ie a PK like MG, an AK like assault rifle, and an SVD like sniper rifle.)