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Old 12-18-2007, 12:08   #1
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Future of the 6.8 spc caliber

In 2005, Remington cooperated with some military designers to roll out the 6.8 spc. Since then, it's been said to have the following advantages for military users:

* Fits in existing AR-platform service rifles (M4's, M16's). All that's needed to fire it is a new upper and a new mag.
* Larger caliber bullet translates to higher probable stopping effectiveness.
* Better energy, ballistics, and range than the 5.56 ammo.
* Lower recoil than an average .243 round.


However, what I've noticed is that despite an initial market splash, where some AR rifle makers rolled out 6.8 rifles and uppers, the 6.8 has not developed a huge following. Very few places are producing 6.8 factory ammo. And now, there are very few if any hunting rifles being chambered for it, though at first Remington had a couple.

My questions about the 6.8 are:

* Does the 6.8 have a future in the service? I'd love to hear if any recent service folks have a thought on this. Is it the most likely supplement or even successor to the 5.56? Or is that never going to happen, because the military will just stick with 5.56 as the primary round, and .308 as the round for sniping and long-range engagements?

* Does the 6.8 have a future in the civilian section, either as a "sporting/tactical" round, or for hunting, or both? Or, will it continue to receive a rather lame market response as now, and eventually fade into oblivion, just like a lot of other "interesting" calibers of the past?
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Old 12-18-2007, 13:41   #2
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I doubt we will ever use that round because of pressure from NATO to conform. That was the main reason we dropped the 1911.
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Old 12-18-2007, 15:17   #3
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i wish the 6.8 would catch on, i would buy an upper but the gun shops here in SD don't carry the ammo and you have to special order it.if you buy an upper and it fades into the great blue yonder of forgotten shells then your stuck with an expensive upper and mags
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Old 12-18-2007, 18:53   #4
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Just my two cents here. I mean not to stir the pot, but I might. If you don't agree, well, what ever, I don't feel like arguing.

N E WAY

I really do not thing the 6.8 was worth taking beyond prototype stage. It does not offer anything spectacular enough to care about. It is just like the .30TC. BFD another remake of .308, just a couple of thousands shorter overall.

To compare the 6.8 to the 5.56, unless you are speaking of energy at the muzzle, there is nothing to compare. 200 ft/lbs difference @100 yards is nothing when considering you are using ball ammo, that will fully penetrate anyway, and will leave a tiny hole. The difference between .22 and .26 caliber. WOW If you were talking about using modern hollow point or mushrooming ammo on game, I would humor you. But we have to look at this in the perspective of military intelligence. Ball ammo is what you get.

5.56 shoots flatter, though the 6.8 has better resistance against wind. In the wind department neither hold a candle to .308 (aka, both suck) You can still carry more 5.56. It is still cheaper to load 5.56, 5.56 components and tooling are more common.....I can keep going.

Basically, unless the 6.8 came out with all the good points of 5.56 combined with all the good points of7.62X63 (no, not 7.62X51, though that would be fine too), and none of the bad points of either, there is no reason to switch.

IMHO, if you want an AR with more punch than .223, get a .308 upper and be done with it. In defense of this all, I am a huge fan of .223. It has great qualities for all kinds of sport. I just think it should have NEVER even been considered for use on human size targets, unless made of paper.
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Old 12-19-2007, 07:03   #5
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If there were a 308 upper for my AR15 I would be very happy.
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Old 12-19-2007, 13:18   #6
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Originally Posted by Zydeco76 View Post
If there were a 308 upper for my AR15 I would be very happy.
http://www.rguns.net/010_64.html
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Old 12-19-2007, 16:21   #7
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Just trivia, but I don't think you can put a DPMS .308 upper on an AR15 lower. You need the AR-10 type of lower that has the larger magwell required by the mags that hold the .308 rounds.
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Old 12-19-2007, 19:31   #8
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Well, to be honest, I know little about the AR platform. I have always preferred the M1A/M14 platform.

It seems that I may have burst some bubbles here. Sorry, but, I warned that it could happen. You asked my opinion, and were given it. Remember that what I wrote above is my opinion. If yours differs, then ignore me and do what makes you happy.
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Old 12-19-2007, 21:22   #9
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No worries, no bubbles. I have no personal interest in the 6.8, don't even own one, just curious about its future and inviting opinions. Yours is indeed welcome as is anyone else's. Just thought it was worth pointing out that you cannot put .308 platform uppers, which are based on the original Ar-10's, on an Ar-15 lower.
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Old 12-20-2007, 15:12   #10
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One other interesting note about the 6.8. I still have no plans to adopt it myself, simply because I'm pessimistic that it will ever be adopted by the military, and so I'm betting it'll always remain a rather marginal cartridge in the civilian sector as well. That's the reality, but it's also too bad, because I've changed my mind about the effectiveness of the 6.8. Based on the info below, I think it would be a more effective service cartridge for our military, giving our troops exactly what many of them are asking for in surveys: a caliber with more effective stopping power, but that still has controllable recoil during full-auto or burst firing, is light enough to carry a lot of it, and can still be used on an AR15-platform rifle (with a barrel, bolt, and mag change). But, just as we've learned with the recent JCP pistol competition in the military, the best or even the good options aren't always what we provide to our service folks, because there are so many political factors involved. In the case of the 6.8, that's too bad, I really wish we could put this round in the hands of some troops and give them a chance to field-test it. I'm pretty confident our troops would love this stuff because of its stopping power and performance.

I used to think the 6.8 was just a cartridge looking for a reason to exist, with only very modest or marginal gains in energy and performance over the 5.56 ammo issued by the service (I'm speaking specifically of the 62gr steel-tipped issue ammo, and the newer "Mk 262" 77gr stuff that some units are using with success at longer ranges). But after looking into this a little bit, I've changed my mind. I think that the 6.8 actually DOES offer a pretty good boost in energy and stopping effectiveness over the issued 5.56 ammo. I based this on a number of shooters I know who are experienced both with shooting 5.56 service ammo, AND have tried 6.8 ammo for hunting, and they confirm its actual stopping power on deer is much higher than any 5.56 or 223 ammo they have tried. This makes perfect sense, because you have a larger caliber bullet, with quite a bit more energy, and equal velocity. Along with those real-world, anecdotal reports, if you compare the energy of the more effective 77gr issued ammo, with that of the common service load by Remington for the 6.8 (115gr), you actually see the 6.8 has significant energy gains over the 5.56 ammo at all distances from the muzzle out to 600 yards. Here's a chart with the data. Based on the chart, the 6.8's energy in ft./lbs exceeds the 5.56 by 737 at the muzzle, by 641 at 100 yards, by 485 at 300 yards, and by 304 at 600.
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Old 12-20-2007, 17:20   #11
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My I ask where that table came from. I got my info from Remington. I figured that since they came up with the cartridge, they would know best.

Anyway, to get 2002 ft/lbs, you need 2800 fps. The 6.8 is advertised, in all 115gr loadings, at 2625 fps. 2002 ft/lbs just became 1759 at the muzzle, and 1410 at 100 yards. 5.56 get 1322 fps muzzle, and about 1100 @ 100 yards. 300 ft/lbs is not enough to make me switch. Both are marginal at best for human targets.....

I think that the move toward a larger caliber bullet is a step in the right direction, but everyone here is trying to have their cake, and eat it too. You simply cannot have a strong cartridge without recoil. So, which one is it? Hit them once or twice really hard, or spray and pray, and put pin holes in your enemy? Just for thought, if you took that 6.8, BLASTED it out the barrel at 3000 fps, you would get 2297 ft/lbs muzzle. Hornady leverevolution in, wait for it, .30-30 has 2150 ft/lbs. Yea, the 6.8 shoots flatter, but so what? You can still barely, and I do mean BARELY, beat out one of the FIRST smokeless cartridges made.........when you cheat and give yourself 400 fps, you don't have!!!!!!!!!

I know I seem agitated about this subject. That is because I am. 5.56 is nothing but .222 magnum with a different shoulder angle. Who the genius decided that the prairie dog slayer would be a good choice for combat? Idiot. Why don't we go back to the drawing board, and come up with something adequate for our brave soldiers to carry? Because, at the moment, they are all around the world, protecting you and I, dieing for you and I, and WE sent them out there with the ballistic equivalent of a whiffle bat. 6.8spc is nothing more than that, but with slightly better plastic.
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Old 12-21-2007, 01:06   #12
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No need to get agitated Verge, you're entitled to your opinion pro or con, that's fine. I'm just indicating mine as well. I'll just indicate that this data comes from a number of sources which all indicated with Remington 115gr 6.8 rounds, people have gotten this velocity of 2800 in a BTHP "match" type of round. For example, this article from Rifle Shooter Magazine shows those chrono'd results for that particular load, albeit in a 24" barreled bolt action rifle. And Chuck Hawks on his rifle ballistics summary page, publishes the same figure, 2800 as the standard MV for the 6.8 115gr. Heck, even the manufacturer's data for the Rem 6.8 115gr shows 2800 MV, as on this page at Sportsmansguide. My guess is, in a 20" M-16 rifle used by a DM for instance, that MV would be a tad lower, and of course a little lower still as you move down to shorter barrels. But of course, you also lose velocity in your 5.56 ammo as you move to shorter barrels too. But, just using the 2800 velocity as a starting point, I plugged the numbers into the Ballistics calculator on handloads.com, where you put in caliber, bullet size and type, MV, and ballistic coefficient, and it calculates the energy for you. I ran the numbers out to 600 yards for a BTHP 6.8 115gr round, and plotted those in Excel, compared to the number for the 62gr, to see how they differ over 600 yards. Clearly the difference in energy between the two trends down the farther you go, but at the muzzle it's a difference of over 700 ft./lbs, and even at 300, it's still 485 ft/lbs. Since most engagements do occur within 300 yards, and the 6.8 was specifically designed to be a more effective CQC round, in my opinion that round would seem to give them a significant boost in stopping power compared to the 5.56. Obviously a much heavier caliber such as the 7.62 would provide even more energy and stopping power, I don't disagree with that. And for many shooting situations, like snipers, the 7.62 is still the best choice. Still, I just think the service is looking at other factors, they seem to still want a round that is light enough so they can carry a lot, keep a fairly low recoil, and still be able to use it on their AR15 platform rifles. And the 6.8 seems to fit, it's too bad that it will probably never get a chance.

Anyway, it's ok if you prefer different calibers. I think we're all on the same side on the issue in general: we all want to see our guys have the tools they need to get the job done, and in the surveys I've seen, they are requesting heavier caliber bullets or better stopping power. In any case, the discussion is academic, because I don't think the 6.8 is going to have much of a future. :-)
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Old 12-21-2007, 04:02   #13
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Tim
You already know my opinion of the AR platform, so I won't go there.
We already HAD a good looking intermedeate round developed before WW-2, it's called the 276 Pederson (25% increase in mag capacity over the -06 and 7.62NATO to boot) and does more than the 6.8 even dreams about doing.
In addation, what the other NATO allies wanted to adapt (before we rammed the 7.62 down there throats) is very similar to the 7mm-08 cartridge in preformance.

Check them out, you might be suprised at what kinds of things we overlooked along the way.
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Old 12-21-2007, 09:18   #14
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Yes, I've heard of the .276, it does sound like a good cartridge. There are so many great ones out there, one of which is the old 6.5 x 55 Swede. I just don't get why we haven't gotten more serious about giving SOMETHING better to our troops. Cheers!
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Old 12-21-2007, 10:58   #15
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IMHFO-the only thing that keeps us from adopting(not developing)an already existing sufficient or superior cartridge is the right people have'nt had their pockets stuffed or their palms greased!We have such a huge amount of cartridges and ballistic data on performance/characteristics that to the average person it would be easy enough to narrow it down to at least 10-15 different rounds that would be useable!I think it's called alliances and kickbacks!
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Old 12-24-2007, 17:21   #16
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Just for a visual referance, some of the cartridges that have been mentioned on this thread

5.56Nato, 6.8SPC, 276 Pederson, 280-30* British experamental, 7.62Nato, 30-06

*280 (7mm) with the same .473 case head dimention as the US 30cals, the first versions used a smaller head diameter.
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Old 12-24-2007, 18:11   #17
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Timlt, If the info you are getting is the wide spread accepted info, then it is what it is. Even still, it is still lacking. Magnomark is correct again. This really has nothing to do with the capabilities, or lack there of, of a cartridge. It has to do with money.
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Old 12-26-2007, 00:35   #18
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I just read a very interesting article by Anthony Williams, a Brit who writes for publications like Jane's Defense and has over 30 years of consulting, collecting, and researching ammunition. The article is titled "Assault Rifles and their Ammunition: History and Prospects." He gives a good historical survey of the calibers/rifles that have been tried, why the various options have been bypassed, and what may be coming next. The article concludes with the need for a caliber more powerful than the 5.56, and lighter than the 7.62, and he mentioned some viable options, including the 6.8 and the Grendel 6.5. Very informative.

In a related development showing that it is often political and bureaucratic opposition that kill a promising new caliber like this, I ran across a report on Defense review that says the 6.8 is getting rave reviews from the SOCOM operators using it against enemy combatants. However, there are apparently some Army brass working hard to kill the 6.8, and also, there are reported to be some production problems at Remington, resulting in a shortage in supply of the ammo. Once again, this illustrates as I mentioned above, I think it's too bad that we have a caliber that was designed by some of our SOCOM folks in the field, and they're telling us that this is an effective round, and yet due to political resistance it is likely that the 6.8 is never going to get very far.

Last edited by timlt; 12-26-2007 at 00:41.
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Old 12-26-2007, 06:35   #19
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Another thing you have to think about is penetration. One of the main reasons we dropped the 7.62 NATO round is it was punching right through enemies. We adopted the mouse gun round partially to stop that and the other reason was we really dont want to kill anybody in war (our switch to 9mm in evidence for that) just wound them. Plus a solider can take 3-4 times the amount of 5.56 into battle with him vs 7.62. War has also changed... We are no longer shooting communists through 700 yards of wooded European countryside. Urban combat is about rate of fire and keeping collateral damage down. Surely our troops get to keep ma deuce around but even at the squad machine gun level they are using 5.56.
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Old 02-02-2008, 00:25   #20
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UPDATE: RUGER chambers the mini in 6.8!
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Old 02-02-2008, 20:59   #21
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IMFHO-we already have an AR platform that can handle any round up to and including the 7.62 nato(.308win)-it's called the ar10,big brother to the ar15.Trouble is that they have been sold-out of this country for so many years and not available here until recent.If you check on ASI's sight it will amaze you the cartridges that can be adapted into the ar10 platform.And even if the military were to completely re-issue all new ar10's-it would be far less expensive than to go to this new modular plastic weapons system that they have been experimenting with for several years.
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Old 02-04-2008, 12:48   #22
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I was very hot for the 6.8spc until I realised that the military wont adopt it, and there goes my cheap ammo supply.
The reason I believe is that Remington can only get it to perform at the velocity they quoted by using a 24" barrel, lets face it the majority of the Armed Forces use the M4 now like it or not and that is a a 16" barrel, and when you do this its so close to the 7.62x39 in fps its not much of an advantage.
Timlt maybe you could run the calcs to see what the fps is out of a 16" barrel ,as the 7.62x39 is about 2330fps with a 124g bullet, I'm sure a real world test was done and posted on this board using a new 6.8spc mini and the results were very, very sad and the conclusion was that you dont gain much more than the 7.62x39 hence it dosn't justify the extra cost.

Bye the bye the 16" SOCOM 308 gets about 2500-2600 fps.
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Old 02-04-2008, 14:30   #23
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Actually 14.5" ...

Colt's website has specs for the M4 barrel at 14.5", so you can appreciate how it's terminal ballistics start decreasing quickly as range increases. A Mini-14 with a 16" barrel ought to perform a bit better in that respect.

http://www.colt.com/mil/M4_2.asp
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Old 02-04-2008, 14:39   #24
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Thanks Mabes, I couldn't remember if it was 14.5 or 16"
Timlt can you run the 6.8spc figures on a 14.5" barrel to get real world figures what the boys in the sandpit would have rather than the 24" fps figures that everyone quotes from Remington when trying to compare it.
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Old 02-04-2008, 15:13   #25
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That would be true of most ballistics figures that are cited standard from the manufacturer, that they give the results from a long barrel, typically 24", and the results must be adjusted downward for any shorter length barrels used. Obviously if you use a 14.5" M4, you're going to get reduced ballistics with the 6.8 spc, and also with 5.56, with 7.62 or with any other ammo we might try to use. You can of course calculate what the lower ballistics would be from a lower barrel, but it's important then to do the same for every other load you're comparing it to. I still suspect you're going to see roughly similar ballistic differences between the various loads being considered here, if you compare all of them being shot out of say a 16" barrel.

For instance, on the Defense Review site, they suggest that they are still getting pretty good performance from this cartridge, even with the 16" barrel. If the 2600 f.p.s they are repoting is correct (and I have no way of knowing if it is), then that would still give them pretty good ballistics over 5.56, even from a 16" barrel, especially within the first 300 to 400 yards.

"It would appear that military operators would have good reason to have confidence in the 6.8x43mm SPC. According to noted gunwriter Gary Paul Johnston, "For military purposes, the 6.8mm SPC outshoots anything in its class--including the 5.45x39mm, 5.8x43mm [Chinese Army's standard infantry rifle cartridge], 7.62x39mm, and even the 6.5mm Grendel. Producing increased incapacitation at all ranges out to 600+ yards, the 6.8mm round fires a 115-grain Hornady Match or Sierra Match .270 caliber bullet at over 2600 fps (feet per second) from a 16-inch barrel M16 type rifle called the Mk-12 Variant "Recce", and has essentially the same trjectory as the M118 7.62mm NATO Match cartridge. A conceptual 6.8mm SPC version of the Special Purpose Rifle (SPR) also exists. The 6.8mm SPC is at least as accurate as the 5.56mm NATO and 7.62mm NATO rounds now used by U.S. Military Forces." (November 2004 Issue of "Guns & Weapons for Law Enforcement" Magazine, p.62)."

[Added]
Sorry, forgot to respond to your other question. While the ballistics calculators I use don't have an option for factoring in barrel length, it's not that hard to play out the numbers. Chuck Hawks cites a Remington publication that states that for centerfire ammunition with a MV of 2500 to 3000 fps, for every 1" drop in barrel length you get approximately a 20 fps reduction in velocity. So if the 6.8 ammo published results assumed a 24" barrel, you'd take 8" times 20, which gives you 160. Subtracting that from the published result of 2800, it would give around 2640 fps. Since the above tests with a 16" barrel said they were getting 2600 fps, that seems pretty close, and is still significantly better energy and stopping effectiveness (considering the larger bullet mass) compared with a 5.56 coming out of a 16" barrel. That's probably why they Spec Forces groups using it were so positive about it, according to the above report.

"The 6.8x43mm SPC, according to DefenseReview sources, has been performing extremely well in the field against enemy combatants. Special Operations end users are thus, reportedly, very pleased with it."

Last edited by timlt; 02-04-2008 at 15:32.
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