[Tony Williams]

This has been published in strategypage.com:

"January 6, 2005: The new 6.8mm rifle round developed for SOCOM (Special Operations Command), will be available commercially later this year as the 6.8mm Remington SPC (Special Purpose Cartridge). The manufacturer says the round won’t be available to the public until the middle of the year, because of the need to produce sufficient quantities of the round for military contracts. There have been some problems in manufacturing the 6.8mm SPC. Remington began work on the new round in 2002. It used the case from the old Remington .30-.30 (which was not a true .30-.30, as it was rimless.) SOCOM has been testing the 6.8mm round in M-16s and M-4s modified to accommodate it. The 6.8mm round is more accurate at longer ranges and has more hitting power than the 5.56mm round the M-16 was originally designed for. Out to about 600 meters, the 6.8mm round has about the same impact as the heavier 7.62mm round used in sniper rifles and medium machine-guns.

During the 1930s, the Germans studied their World War I experience and concluded that a less powerful and lighter rifle round would be more effective. This resulted in research on a smaller 7mm round, but with World War II fast approaching, this effort eventually produced a shortened regular (7.92mm) rifle round. During that war, the Germans developed the first modern assault rifle, the SG-44. This weapon looked a lot like the AK-47, and that was no accident. The SG-44, like the AK-47, used a shortened rifle cartridge that was developed before the war (7.92mm for the Germans, 7.62mm for the Russians, which is still used in the AK-47). This gave the infantryman an automatic weapon that could still fire fairly accurate shots at targets 100-200 meters away. The SG-44, and the AK-47, had about the same stopping power as the 6.8mm SPC at those shorter ranges. What a coincidence. The AK-47 didn't have the accuracy of higher powered bullets, but the Russians didn't see this as a problem, because most troops using it had little marksmanship training. If they had to kill someone, they could fire at full auto. The U.S. M-16, and its high speed 5.56mm round, was more accurate than the AK-47 when firing individual shots at shorter ranges. But the wounding power of the 5.56mm (.22 caliber) bullet fell off rapidly at ranges over a hundred meters. The American military, and especially SOCOM, train their troops to fire individual shots, and do it with great accuracy at any range. A number of new rifle sights have made even easier to do, and makes first round hits at longer ranges easier to make. This made the longer range shortcomings of the 5.56mm round more obvious.

SOCOM has been using the 6.8mm round in Iraq and Afghanistan, and the users like it. But there is resistance from senior (non-SOCOM) generals to any consideration for replacing the 5.56mm round with the 6.8mm. To further complicate matters, there’s a new 6.5mm “Grendel” round being tested as well, and some troops prefer it to the 6.8mm SPC. This is because the 6.5mm round is more accurate than the 6.8mm one at ranges beyond 500 meters. At the moment, no decision has been made about any replacement for the 5.56mm round."

Now this contains some obvious historical errors and confusions concerning the '.30-30 Remington' and the development of the 7.62x39 and AK-47. However, the interesting part is the claim that not only is the 6.8mm Rem SPC undergoing what sounds like substantial field testing in Iraq, but that the 6.5mm Grendel is being tested by the military as well. Can anyone substantiate this and provide any details?

Tony Williams: Military gun and ammunition website (http://www.quarry.nildram.co.uk) and discussion
forum (http://forums.delphiforums.com/autogun/messages/)

[Preacherman]

Yes, both are being tested, and I've spoken to some SpecOps folks whom I know about it. Of course, details are not available to the public as yet.

A couple of points. The 6.8mm. round was developed by Remington as a SpecOps co-operative project. One of the design criteria was that the new round had to fit as many as possible into a standard 30-round AR magazine. For this reason, a relatively "thin" cartridge case was developed, so that 26-27 rounds can fit into the AR magazine.

The 6.5mm. Grendel was a private development, which did not have magazine capacity as one of its design criteria. The case is "fatter", which means that less of them (22-23, IIRC) can fit into a magazine in comparison with the 6.8mm. round. This is seen as a drawback in combat situations.

Apparently the 6.5mm. round is definitely more accurate at longer ranges, but not so much as to be a disqualifying factor for the 6.8mm. We're talking about the ability to hit a 10-inch target at 800 yards versus hitting a 20-inch target at the same distance (in the hands of combat operators, from combat firing positions). Since very, very few shots are taken at that sort of range, it's not considered to be of earth-shaking importance.

The initial reports from the field speak of a distinct improvement in one-shot performance on opponents at short to medium ranges. However, at longer ranges, there isn't much "wound improvement" over the 5.56mm., as the bullet doesn't expand or fragment at lower velocities. It does, of course, carry better at longer ranges, due to a better BC.

[buttrap]

Sounds like a company press release to me..mostly hype and not much fact...

[Bigfoot]

I think they missed the mark when they specified the 6.8 had to funtion from 5.56 mags. They could have had more powder capacity or a shorter case for longer bullets if they had manufactured mags without the ribs. I understand it's because of the numbers of mags we are talking about but mag bodies arn't all that expensive.

Here is the 17 rd. 6.5 Grendel AR mag with no ribs. Just about the same length and capacity as the 5.56 mags loaded with 6.8 SPC.

[Gewehr98]

The old .30 Remington was often referred to as the .30-30 Remington, to illustrate it's ballistic likeness to the rimmed .30-30 Winchester, aka .30 WCF.

Myself, I'm working on a .26 Remington wildcat for the same AR-15 type of application. :D

[Tony Williams]

The initial reports from the field speak of a distinct improvement in one-shot performance on opponents at short to medium ranges. However, at longer ranges, there isn't much "wound improvement" over the 5.56mm., as the bullet doesn't expand or fragment at lower velocities. It does, of course, carry better at longer ranges, due to a better BC.

Thanks for the response. Does that just apply to the 6.5mm Grendel, or to the 6.8mm as well? I had heard that the 6.8 remained effective out to fairly long range.

Tony Williams: Military gun and ammunition website (http://www.quarry.nildram.co.uk) and discussion
forum (http://forums.delphiforums.com/autogun/messages/)

[Tony Williams]

The old .30 Remington was often referred to as the .30-30 Remington, to illustrate it's ballistic likeness to the rimmed .30-30 Winchester, aka .30 WCF.

Interesting, I've only ever seen it referred to as the .30 Remington. Anyway, the phrase "It used the case from the old Remington .30-.30 (which was not a true .30-.30, as it was rimless.)" is rather garbled. If he wanted to spell it out, he should have said something like: "It is based on the old .30 Remington case, which apart from being rimless was similar to the rimmed Winchester .30-30."

Tony Williams: Military gun and ammunition website (http://www.quarry.nildram.co.uk) and discussion
forum (http://forums.delphiforums.com/autogun/messages/)

[kaferhaus]

Sounds like a company press release to me..mostly hype and not much fact...


I too have been less than impressed...

I"m not saying these are not/cannot be "effective" rounds, but the numbers they've released and looking at the case capacities, I can't see where they've accomplished much in regards to what the object was.. which would seem to be better terminal performance at longer ranges..

The 223 is VERY effective until the velocity drops down to 2500 fps or so where fragmentation becomes "iffy".

With the exception of very few instances in Afganistan, I haven't even seen where there's an issue to be addressed.

Both these rounds seem as though they'll be as effective as the current issue stuff at short range, but at longer range.... unless they design some "special wonder bullet" that meets the Geneva rules I don't see it.

For MY uses, with sporting bullets you could turn your AR into a very effective deer getter maybe.... but I'm not gonna pony up the kind of money they're asking for one of the uppers.

I kill deer just fine with mine now with the Nosler partitions.

The 6.5 is doomed as a military round unless they adopt some "special ops" limited type role for it. It would require too many logistical changes.

The 6.8 might have a better chance until someone up top says "why?"

In any event the army would put either of these two through years of testing and logistics studies before they made any decision on replacing the 5.56.

By that time the next "wonder cartridge" will be out.

I think the real "deal" on both of these is to get the internet commandos/weekend warriors frothing at the mouth to buy one.

If either or both of these make it as a commercial round, I'll wait a couple years until everyone and their brother is making them and then perhaps buy an upper or barrel and try one out for hunting. The 6.5 seems to have more potential for that... I don't need a 30rd mag to go after bambi.

[Otony]

Actually, Remington initially stamped their Model 8 rifles, .30-30 Remington. Complaints from Winchester soon stopped that practice. I have seen more than one Model 8 so stamped.

The .30 Remington round is pretty close to an EXACT duplicate of the .30 WCF/.3-30/Thutty-thutty save for the lack of a rim.

I will agree that the stament in the article is very poorly worded, and the AK-47 references are jumbled as well.

[TrapperReady]

Just for comparison, here are two factory-loaded 170gr cartridges. The one on the left is .30 Remington, while the one on the right is .30-30 WCF. BTW, they're both Core-Lokts.


http://www.fototime.com/%7B589CD9BC-6340-4D41-8AFA-0D6F76A9A7C7%7D/picture.JPG

[Grendelizer]

Kaferhaus makes some good points, and I'll take them in order:

KH: "The 6.5 is doomed as a military round unless they adopt some "special ops" limited type role for it. It would require too many logistical changes."

G: Since there was no official military requirement to create the 6.5 Grendel for an official military program, it was conceived to stand on its own to give AR15 shooters and others a compact, intermediate cartridge with long-range capability. It stands very well on its own, thank you, for competition, LE, and hunting.

Having said that, the fact that it is the embodiment of the best military thinking on a small arms cartridge that came out of the vast experience of World War II, and is the most logical inheritor of the British .280 concept, makes it ideal, in my opinion, to become the next modern military cartridge replacing both 5.56 and 7.62. But I've argued that point elsewhere, and I'll stick to the specific points here.

KH: "The 6.8 might have a better chance until someone up top says 'why?' "

G: Someone at the top has already said, "Why?" At the SOCOM "trade show" event in May of 2004, military authorities announced that there will be no official procurement of the 6.8 SPC. Though it's creation and adoption was and is spearheaded by Sgt. Steve Holland of 5th Special Forces, it is, by the admission of the 6.8 SPC developers themselves, a semi-private venture. That Remington and Barrett picked up the program with visions of selling many, many units of ammunition and rifles to the military on the taxpayer dime does not reflect official U.S. military policy.

KH: "In any event the army would put either of these two through years of testing and logistics studies before they made any decision on replacing the 5.56."

G: How true, and this, of course, properly should be done.

KH: "I think the real 'deal' on both of these is to get the internet commandos/weekend warriors frothing at the mouth to buy one."

G: I agree with this. Remington and Barrett's marketing strategy almost depends on the "cool" factor of being able to say that the "cool" military guys are using it, therefore you should buy it. In all the forums I frequent, I can't recall much at all by Alexander Arms trumpeting any military connection to their cartridge. I know I mentioned something once on AR15.com, but that was only to correct some guy implying that the 6.5 Grendel was in extensive use in Iraq. As far as I know, and this is news from months ago, any Iraq connection and the 6.5 Grendel was VERY limited. Alexander Arms, dating from into the Cold War years, is quite experienced dealing with hush-hush, real-deal military projects and is not about to go blathering details over the internet on public forums!

And these statements that Remington can't release commercial 6.8 SPC because it has been filled to capacity with military 6.8 SPC is, IN MY OPINION, just two stiff drinks short of an outright marketing lie. Remington has been telling us since early 2004 that it's been busy filling military orders. When one of their loading machines can make 3,000 rounds an hour, how many million rounds are we supposed to believe have been made in a year? And you only make rounds for guns, so how many guns are supposedly out there needing to be fed by these millions of rounds? Is anybody claiming that thousands and thousands of 6.8 SPC rifles are overseas being "tested"?

Do you think the U.S. military has bought more than $25,000 worth of 6.8 SPC ammunition? If so, then who can, please, provide us with a government contract number that we can reference using the government contract website: www.fbo.gov?

Could the truth be closer to what the independent testing of Hodgdon Powders has revealed? (See http://www.hodgdon.com/data/rifle/68mm-rem-spc.php .) Remington and Barrett promised us 2650 fps from a 16.5" barrel. The maximum that Hodgdon could get in their independent testing was 2608 from a 24" barrel, and that at a pressure of 53,300 psi, a pressure which, in this class of cartridge, is getting to dangerous levels in a standard AR15/M16.

Even the gel-test photo which shows an "optimum wound profile" for the 6.8 115gr Hornady OTM as first promulgated on www.tacticalforums.com notes it was done using a velocity of almost 2700 fps in a 16" barrel at nine feet. How would that gel test look if done with a load that gets 2608 in a 24" barrel, and then is further reduced to a 16" barrel?

My analysis is that Remington could not SAFELY get a MASS-PRODUCTION round to live up to its velocity promises, and realizes there is ultimately not that much future in a ho-hum cartridge. Unless, of course, they can hype it up that the "cool" spec ops guys are using it, and therefore you should, too!

In defense of the 6.8 SPC, it has always been claimed to be a "Special Purpose Cartridge." But even in that role, if its velocity stays under the promised figures, how much better will it be than a standard, and much cheaper, 7.62x39 Russian? In and of itself, it's not really a bad round; my objection is to the hype generated around it by those greedy for it to succeed.

If you want to get "general purpose performance" from a compact, intermediate cartridge with moderate velocities, you've GOT to have a high BC bullet or you're simply reinventing the Russian 7.62x39. Enter the 6.5 Grendel, but I've already made those arguments and my response here is long enough!

John

P.S. And though I like StrategyPage and visit often, I have found their pronouncements on 6.8SPC and 6.5G, based on what I know, to often be less than reliable.

[Zak Smith]

Hey, where are those 6.5 Grendel ballistic gel reports with the desired short neck? Oh yeah, there aren't any! :neener:

Point of fact: 6.8SPC does NOT work from USGI 5.56 mags.

See the FAQ for more info.

With regard to velocity, I have information from a first-hand source that the latest batches of ammo are running at 2530fps from a 12" barrel. That will translate into over 2800 from an 18". To your comment of 2608fps from a 24" barrel-- us 6.8 reloaders are getting 2600fps from several conventional powders in 18" barrels.

The threshold for that good profile presented in the NDIA report is somewhere between 1700 and 2200fps. If we split the difference at 2000fps, that's still 200 yards from a 12" barrel, or about 300 from 2700fps (which is what the preprod ammo I've got shoot - and within striking distance of our reloads). 6.8SPC was designed for optimum wound profile with acceptible velocity from 0 - 300 meters in 12-16" barrels.

The strategypage blurb has absolutely NO new information.

[Grendelizer]

Zak, while I've got your ear, do you happen to have a government contract number for either rifles or ammunition? Or perhaps check your "first-hand source" and see if he's got a number I can use to reference on www.fbo.gov. Seriously!

John

[BigG]

...has more hitting power than the 5.56mm round the M-16 was originally designed for. Out to about 600 meters, the 6.8mm round has about the same impact as the heavier 7.62mm round used in sniper rifles and medium machine-guns. *snort* *guffaw* where have we heard this before relating to anything new in the military? "Quote, Oh yeah, the 9mm hits just as hard as the .45 and there are more of em in the NEW gun! Unquote" :banghead:

[Zak Smith]

That's it, I'm going back to a single-shot .45-70.

[Preacherman]

Guys, can we please forget the hype and argument of gun (and other) boards on this? The facts are:

1. Both rounds have been and are being tested by small segments of the military.

2. There is currently no prospect whatsoever that either will replace the 5.56x45mm. round as a general-issue item.

3. Both rounds are an interesting exercise in ballistic development. Whether or not either becomes a "stayer" in the already-overcrowded ammo market remains to be seen.

4. Zak, contrary to your information, the 6.8mm. SPC will indeed work from 30-round AR magazines: all that is required is replacement of the follower. I've personally seen this.

BTW, for those wondering about my SF contacts, I work for a Federal agency that has many ex-servicemen in its employ. A proportion of these are ex-SF, who remain active in the reserves, and several have been called up for foreign service over the past few years. Others are called up on a short-term, regular basis to instruct others. It's these folks who've been involved in the T&E of these rounds, and I've obtained my feedback from them at first hand. I've also had the opportunity to look at an AR-15 used for testing 6.8mm. ammo, and thus have some idea of how it looks in practice. (No, I wasn't allowed to shoot it... :( )

[Zak Smith]

4. Zak, contrary to your information, the 6.8mm. SPC will indeed work from 30-round AR magazines: all that is required is replacement of the follower. I've personally seen this.
All the USGI 5.56 mags (edit: 30 round) I've tried bow outwards after 8-10 cartridges are loaded such that they will not fit in the mag well. I don't see how the follower could affect that. How are the followers changed?

FWIW, the only difference between the Magpul Anti-Tilt 5.56 followers and the followers PRI is shipping right now is that they've lowered the 1st round shelf to correpsond to the difference in cartridge diameter. (A modification I pioneered in Sept '04.)

If 6.8SPC did work properly in USGI magazines, why would PRI & others have invested thousands in R&D of new 6.8-specific magazines?

-z

[Grendelizer]

Preacherman, I'd be very interested in any feedback you have from these guys on the 6.5 Grendel. If you feel its dissemination is improper on a public forum, please PM me. Thanks!

John

[Preacherman]

Zak, the AR mags I saw with the 6.8mm. rounds were not the USGI aluminum magazines, but rather steel mags (perhaps the British-production mags for the SA80? I don't know.). That might explain why these worked, where the aluminum magazines didn't: the stiffer steel mags would be more resistant to the "bowing" effect.

[Zak Smith]

Are you sure they weren't the steel PRI 6.8SPC mags? They look like this (minus the Magpul baseplates):
http://apollo.demigod.org/~zak/DigiCam/6.8SPC/?medium=129_2906_img.jpg

[Gordon]

They shoulda used 6.5 Ugalde which is the .223 necked to 6.5mm ! Then all it woulda taken is a rebarrel . The small case burns optimally in about 12" barrel. A 115to 120 grain bullet can get 2500fps in a 14" barrel(my contender) with a hot load-easily. My wife's Sako gets 3/4 moa at almost 2700fps from it's 22" barrel. Negligable recoil and a deer buster for sure to 300 yards. I guess it takes a team of engineers to earn their salaries though! :banghead:

[Zak Smith]

1. No 6.5 bullets have exhibited the desired terminal effects as tested via the standarized protocols, in pariticular, they have long "necks" before they fragment. Ask DocGKR about this specifically if you want detail.

2. 6.5 TCU has about 10gr less water capacity than either 6.8SPC or 6.5 Grendel. It won't be able to achieve close to the same velocities. The first google hit for 6.5 TCU was this: IHMSA: BULLBERRY 6.5 TCU By: Todd Spotti (http://www.lasc.us/RangingShotBullberry6.5TCU.htm) and he reports the "blistering velocity" of 2500fps for the 85gr bullets, while the 120gr bullets are only at 2300fps. That's with a 15" barrel. He doesn't mention the OAL, but this link does http://www.ihmsa.com/shooting_with_the_winners.htm 2.750! No way in hell that will fit in a M16 magazine. The longest that will fit in the PRI 6.8 mags is about 2.290 - 2.300", while 223/556 standard is closer to 2.25".

If you want to debate Caliber X vs. 6.5 or 6.8, let's start a new thread. This one's reserved for 6.5 vs 6.8! :D

[Tony Williams]

Just for comparison, here are two factory-loaded 170gr cartridges. The one on the left is .30 Remington, while the one on the right is .30-30 WCF.

Not that similar, then - the shoulder angle is quite different.

Tony Williams: Military gun and ammunition website (http://www.quarry.nildram.co.uk) and Discussion forum (http://forums.delphiforums.com/autogun/messages/)

[Preacherman]

Zak, I don't know. I was informed by Those That Knew that the mags were "standard 30-rd. M16 steel mags". They didn't mention any mags specially for the 6.8mm., and since I have a few of the British steel mags for the SA80, I was able to do a mental comparison, and found them similar.

Doesn't help, I know... ;)

[Zak Smith]

Well, I might pick up one or two SA80 mags to find out.

[Gewehr98]

Not that similar, then - the shoulder angle is quite different.

The fired brass from my .30 Remington Model 8 rifle looks a lot closer to the .30-30 Winchester's.

And Remington's reason for the round was to duplicate the .30 WCF/.30-30 Winchester's ballistics in an autoloading/pump rifle. So case capacity was the biggest factor. The shoulder design was probably tweaked to enhance feeding from the box magazine of the Browning-designed Model 8, just like the removal of the rim.

On a side note, I'm working with the Lapua and Lost River Ballistics 6.5mm offerings on my larger 6.5mm rifles. I've got to get busy on my 6.5 SPC/.26 Remington AR-15 project - .277, indeed! ;)

[Tony Williams]

The shoulder design was probably tweaked to enhance feeding from the box magazine of the Browning-designed Model 8, just like the removal of the rim.

Actually I suspect that the shoulder was made sharper because of the absence of the rim, in order to provide accurate headspacing.

Tony Williams: Military gun and ammunition website (http://www.quarry.nildram.co.uk) and Discussion forum (http://forums.delphiforums.com/autogun/messages/)

[only1asterisk]

It would appear that little has changed in the positions of the interested parties in the last 8 months. I went back and found:http://www.thehighroad.org/showthread.php?t=77366&page=1&pp=25&highlight=6.8+spc (http://http://www.thehighroad.org/showthread.php?t=77366&page=1&pp=25&highlight=6.8+spc) I reread the posts of 8 months ago and find no consensus seems to have formed. The proponents of both cartridges still expound their virtues, while there remain some doubts about both.

There have been some developments. Several companies now produce 6.8 SPC barrels and uppers. Bolts are available, as are reliable magazines. Bulk brass for the 6.8 SPC has become available (if on an inconsistent basis) and loaded ammo is available from small volume loaders.
At one other company has been permitted to produce 6.5 Grendel parts. Brass and loaded ammo are available.

I believe the major stumbling blocks are feed reliability in the 6.5 and the inability of the 6.8 to meet performance goals at acceptable pressures. If I had to pick one (in an AR) today it would be the 6.8 SPC.

David

[Grendelizer]

David wrote: "If I had to pick one (in an AR) today it would be the 6.8 SPC."

Well enough, but the question I find interesting in these discussions is, "Why?" Care to expound?

John

[Zak Smith]

I saw 6.8SPC ammo at a vendor at the Denver gunshow this weekend. He had at least three boxes of 115gr OTM at about $12.50 per box. It was not Remington, but some other smaller manufacturer (not PCA).

I spoke to somebody recently who had shot about a case (1k) through the Barrrett 468, sometime in the last month or two. He said it was running perfectly. The latest lots of the testing ammo were running about 2500-2530fps from the 12". That should meet the 2800fps published number but from an 18" barrel (instead of 24").

-z

[only1asterisk]

Grendelizer,

If I were in Iraq, Afghanistan, Pakistan, etc. and subject to being shot at 24/7, the bit of extra reliability I imagine the 6.8 SPC to possess would easily outweigh the Grendel’s “advantages”, even if the return were doubled.

IF I wanted an AR for long range target competition, then the Grendel might be an option. If AA can convince me that they can build rifles that will feed reliably from untweaked production mags, a major US manufacturer tools up to produce brass and they drop the “proprietary” marketing and set their sights on selling things, the 6.5 Grendel will take a huge step forward. If AA continues to try to treat the cartridge like the product instead of uppers, brass, mags, dies, ammo and parts, the 6.5 Grendel will be nothing more than an entry in COTW. It will be a shame too, because the cartridge is a fine design for many applications and the brass they import is top notch.

Zak,

You’ll have to forgive me if I’m a bit skeptical of the velocities. I know that with the resources available to the major manufactures they can do some amazing things. I don’t doubt that a cartridge specific powder could be developed and combined with new packing techniques can get velocities above and beyond what I can produce by handloading. Until green and yellow boxes are just a phone call away and everyone can clock them for themselves, I’ll have some doubts. When you get your hands on some OTC production ammo from big green and run it across your chrono, I’ll not question your results.


David

[Zak Smith]

1*,

I know. It's the best I can do for now.

-z

[only1asterisk]

Understood, just wanted to make sure that nobody got the wrong idea.

David

[NMshooter]

If better 7.62x39 ammo were available, would that change things?

Something like Mk 262 Mod1, an improved performance cartridge.

[Tony Williams]

I think that would be difficult, because the 7.62x39 was designed with a large-calibre, short bullet. if you loaded it with a long, heavy bullet comparable with the Mk 262 in 5.56mm then the muzzle velocity would drop dramatically, partly because of the extra weight, partly because to keep the overall cartridge length the same (essential to operate in the gun) the bullet would have to protrude deep into the case, reducing the propellant capacity.

What you would need to do to improve the long-range performance would be to reduce the calibre to, say, 6.5mm, then straighten the case a bit to improve the propellant capacity, then voila! You have the 6.5mm Grendel :D

Tony Williams: Military gun and ammunition website (http://www.quarry.nildram.co.uk) and discussion
forum (http://forums.delphiforums.com/autogun/messages/)

[Grump]

How much extra performance would we get by blowing the Grendel's shoulder forward another 3mm and ditching the 120+ grain bullets? Even with the great BCs and marvelously small amount of wind drift, I believe that the heavier bullets reduce the first-round hit probability with their more rainbow-like trajectories.

Looks to me like the 100-107-gr bullets come close enough to M80 Ball performance (a tad better, IIRC) to allow a reasonable substitution for both 5.56mm and 7.62x51 ammunition in the supply/arms chain.

And what's really the advantage of 6.5mm over 6mm anyway? Tubb's 6XC is too much like a .243, it's too long for AR magwells (should that REALLY be a major consideration???), and it gets too few rounds per pound of those military metals to be a *wise* choice...but it's a super-accurate 6mm...

[NMshooter]

Actually I was wondering about short range performance. Increasing the wounding potential. If I recall correctly, the 6.8mm was developed to provide increased short range effectiveness.

Our military already has tons of weapons far more effective at long range than a rifle.

[Zak Smith]

Superior terminal effectiveness with acceptible trajectory within 300 yards.

[bnolsen]

This whole argument of 6.8 vs 6.5 or 200 vs 35000 is entirely stupid because of the artificial case length restriction.

Facts -

The AR-15 provides less than acceptable battlefield reliability and maintainability.
The 5.56x45 nato provides less than acceptable ballistics.
Trying to cram a heavier bullet with better ballistics in a short cartridge results in less than acceptable velocities.

Answer:

Design a new rifle to fire a new cartridge!!!
Use a longer cartridge length to accomodate a longer bullet and provide enough powder to give desired initial velocity and acceptable long range performance.

:cuss:

[Grendelizer]

BNO, I disagree. While it's true that a case length is "artificially" or "arbitrarily" chosen, I think the current OAL of the 5.56/6.8SPC/6.5G is both useful and necessary because it disciplines gun and cartridge designers to keep their designs as compact and lightweight as possible, which is also a consideration in the overall picture of a military round. We can't focus purely on "maximized" performance of the round itself, without any consideration of the other factors of size and weight.

Everything in cartridge and weapon design is a compromise, but we're looking for the "optimum compromise"!

John

[Zak Smith]

The 77gr Mk262 5.56 ammunition has a velocity in the same ballpark as both 6.8SPC and 6.5 Grendel loads. The 77gr is superior to M193 w.r.t terminal ballistics at any range from any barrel length (with the possible exception of barrier penetration). Thus your argument about velocity is poor.

Grendelizer is right on about size and weight of the platform itself. Think about a 12"-barrelled "M4" used while mounted (vehicle). In 5.56-length cartridges including 6.8, this is a viable platform for rapid aimed fired, aimed burst, and controlled full auto fire. A 12" 308 will be much heavier, make for a larger weapon, and will be much harder to control.

-z

[only1asterisk]

While I agree with Zak and John about the need to keep the platform as trim as possible, I don't think weight (or size) would really be much of a factor in lengthening the receiver of an AR 15 10mm. The problem would be one of cost.

I see larger rounds being adapted to the AR platform as an interim measure. We have learned a lot on the last 50 years that isn’t reflected in the AR. While it is a mature system, I think the time has come to think about replacing it and the 5.56.


David

[Zak Smith]

I don't think weight (or size) would really be much of a factor in lengthening the receiver of an AR 10mm. The problem would be one of cost.
The difference in the OAL of 308 and 223 is only 0.5 - 0.7", but look at how much larger the AR10 receiver and BCG are vs. the AR15's.

[Grump]

It seems that it would take only .20 of an inch, or 5mm, longer in the mag length/case length to get our 105-gr or so 6.5mm bullets reliably up to the speeds which meet or exceed the M80 ball trajectory AND significantly improve on the wind drift figures. Ammo stays lighter than 7.62mm stuff, you might could stay with the slightly smaller SPC case body for insignificanly (IMO) better ammo stacking, and you would also have a chance then to design greater safety margins in the bolt lugs. . . AFIK, the bolt thrust is a factor for ammo pressures in BOTH the SPC and the Grendel.

Both are, really, stopgaps with various compromises to fit in the M16-size AR package. Stretch that lower to move the trigger group back for the bigger mag well (but keep the assembly pin locations the same), and the upper might need no changes to make it work? Looks to me like the bolt carrier traveling back 5mm farther to pick up the round would affect only the buffer. All other parts would stay the same, though I would argue for an M1 Carbine-style tappet piston at the end of the gas tube...maybe.

Cast in some sand cuts in the upper and put a few in the bolt carrier and the AR might be easier to keep running in the crud.

Seems we're married to the current system by virtue of existing magazines, just like we wound up married to the '06 after WWI because of the ammo on hand. But since we're low on ammo and the cost of the average grunt's ammo fired in combat far exceeds the costs of those magazines, why not just make the next rifle a better round that will let us again unify major parts of the supply system. REPLACE ALL 5.56mm AND 7.62mm with ONE ammunition that has advantages over both. Done right, the only "compromise" from the 7.62mm will be slightly lower kinetic energy...but that's what the .50 is for anyway. :cool:

[kaferhaus]

The AR-15 provides less than acceptable battlefield reliability and maintainability.

BS, this hasn't been an issue since the early 60s, and we don't use the AR15.

The 5.56x45 nato provides less than acceptable ballistics.

Says who? There's been some "anecdotal statements made by a few people", a few instances where the enemy was engaged at ranges exceeding the weapon's effective range, (the enemy's weapons were also outside thier effective range by the way) but I haven't heard any responsible military officer who has any empiracle evidence make such a statement.

Trying to cram a heavier bullet with better ballistics in a short cartridge results in less than acceptable velocities.

True, and the military has nothing to do with these experiments... a few entrepreneurs do.

Design a new rifle to fire a new cartridge!!!

No "need" has been proven for either.

You can't take "exceptional instances" and condemn a rifle/cartridge because of them.

There is no "wonder gun" or "wonder cartridge" or "wonder bullet" that will fill every percieved need for every imaginable circumstance.

If someone comes up with one, rest assured we'd be buying it.

Military procurement of weapons and materials are always going to be the best compromise that will fit the needs of the military over a wide range of potential requirements/uses.

That's the way it is and the way it must be.

[Zak Smith]

True, and the military has nothing to do with these experiments... a few entrepreneurs do.
For 6.8 at least, that is not true.

ETA: Not to mention Mk262 (the 77gr 5.56 loading )

[kaferhaus]

ZAK, I've followed your posts on this thread quite a bit... there may be a "unit" that is somehow testing this of their own volition and if that's the case then the "contractor" is supplying the ammo and equipment for the tests, but the "Army" sure isn't testing it... or put it this way, they don't know that they're testing it...which would be worse...

I can find nothing that shows that any such testing has been authorized or funded and I feel I have pretty good sources... as it used to be my job to oversee many of same.

Small arms testing is not something the Army has ever shown a habit of being secretive about.

So all the things I've read that would indicate this is somehow "hush-hush" makes me take it even less seriously. There simply would be no need for it and it costs a lot more money to test and evaluate something on the "sly", and the funding is MUCH harder to get to do it.

[Zak Smith]

No, if you research where the idea was started, I think you'll find it was a couple NCO's. That's the story I've heard from people who should know.

[dmftoy1]

There's been a few write-ups in the various gun rags about the 6.8spc and they all state that the cartridge was developed (even gives the names) by a couple of NCO's and it has been "purchased" by the groups they're affiliated with. If I remember right they were part of one of the special forces teams and didn't have to go through the normal government procurement.

I'm not 100% sure but I think I read one article in a "Guns & Ammo" that came with a Surefire flashlight I bought..

Have a good one,
Dave

[Langenator]

Would it even be necessary to develop a new cartridge, even if you were going to totally replace the existing weapons and magazines.

Why not simply apply a touch of modern tech to the old Brit EM2 and its 7x43mm round?

[kaferhaus]

A couple NCOs being given permission to use ranges etc. on their own time with equipment and materials supplied by either themselves or others, I can maybe see.. This hardly constitutes "testing" by the Army, or even an Army "unit". The officer giving this permission may have no idea the consequences should there be an accident or even any incident related to this activity.

If you want the real skinny on what the Army has in mind, it's this:

"The XM8 has the capability to switch out barrels, which means you don’t need an M4 and an M16A2,". "You only have one weapon platform and you can configure different variants of what you need. That will really do a couple of things -- it will reduce the logistics tail and the cost of maintaining that weapon and ease the training burden. While the M16 and M4 have operating systems that are about the same, under the XM8, the operating system will be identical. The optics that go with it will be virtually identical. So the training will begin at the basic level. You won’t have guys, for instance, learning how to shoot an M16A2 with iron sights in basic training and then going to the 82nd Airborne and suddenly getting an M4 that’s a modular weapon system with lasers and all that other stuff that they suddenly have to train up on."

"Developmental testing, which was conducted in coordination with Army Test and Evaluation Command, took place during 2004. Depending on the results of that testing, XM8 assault rifles could begin entering the field as early as mid-fiscal year 2006."

Lt. Col. Matthew Clarke, U.S. Army Project Manager for Individual Weapons

No secret "sources", no inuendo.

And for you commandos that don't already know, the XM8 uses the 5.56 NATO.

I've known Matt since he was a 1LT.

[only1asterisk]

For what it's worth, the 6.8's military credentials mean absolutely nothing to me.

I do believe that the 6.8 development stemmed from a .mil request. I remember reading specifications issued several years ago (1998?). It sticks out in my befuddled mind because I was working on a similar cartridge and stopped because of the 6.8 SPC.


David

[Tony Williams]

I agree that the ideal, clean-sheet, general-purpose military cartridge (which IMO would be of around 6.5mm calibre) would have a slightly longer overall length than the 5.56x45 round.

However, there is a very large number of different 5.56mm rifles and LMGs made in many countries of the world, so the commercial success of such a cartridge would be greatly enhanced if existing gun designs could be easily adapted to fire it. Hence retaining the same overall cartridge length is commercially sensible, even though it does enforce design compromises.

Tony Williams: Military gun and ammunition website (http://www.quarry.nildram.co.uk) and discussion
forum (http://forums.delphiforums.com/autogun/messages/)

[Grendelizer]

A brand new article on the 6.5 Grendel has been posted on www.gunblast.com: http://www.gunblast.com/AlexanderArms_65Grendel.htm .

Special Note to Tony Williams: It contains a photo you've been wanting! ;)

John

[Zak Smith]

Nice to see the 6.5 Grendel folks taking the high road :barf: :barf:
http://www.65grendel.com/forum/showthread.php?t=213
(Arne's post #10)

[JShirley]

Let's just be sure we keep that "high road" here.

I have seen NCO's blaze away with a double-bl shotgun on the range when I was with 1-5 Infantry in WA. While it was probably possible to get approval to fire 12 gauge on the range because squad leaders had Mossberg shotguns, I doubt that it was mentioned that any civie shotguns were being fired. ;)
Still, one could claim with something almost resembling truth that a double-barreled, external hammer 12 gauge was being "tested by Army units", or somesuch.

From what I've been able to find on the material, the driving factor for 6.8 (if there truly was one) was close-range performance. 6.5, on the other hand, truly does have the potential to replace both 5.56 and 7.62, and I believe that is a worthy objective.

John

[Tony Williams]

Special Note to Tony Williams: It contains a photo you've been wanting!

Thanks John - but what I really want is the 6.8 + 6.5 + 5.56!

Tony Williams: Military gun and ammunition website (http://www.quarry.nildram.co.uk) and Discussion forum (http://forums.delphiforums.com/autogun/messages/)