The 6.8 SPC could have been a winner if...


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Matt304
July 15, 2010, 02:52 AM
...If it was a 6 SPC instead. :)

My thoughts are that the 6.8 SPC is a ballistic failure. Although, it is only a failure when compared to the 6 SPC. It's not too hard to trump a 55 grain .224. The 6 SPC is a potential big winner. Or, was. I don't nag from a typist's position only. I have enough experience with .277 to know that when you are working with light bullets, ~110gr, it is tramped on by the 6mm.

Here's my frustration. A chance exists to pick any caliber, and .277 is chosen in this day and age? What genius was doing the brainstorming for that cartridge...

I would chamber my rifle for an SPC, but it surely is going to use 6mm bullets. Heck, even 6.5mm bullets would put a ballistic hurting on the .277 choice.

And please don't attempt to use the argument that a .277 mysteriously multiplies the damage to the target over a longer, faster 6mm bullet. :neener:

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Dionysusigma
July 15, 2010, 03:14 AM
... okay... :scrutiny:

Not that I agree or disagree on any particular point, but... where are you going with this? :confused:

Matt304
July 15, 2010, 03:17 AM
You know, just making a random, pointless discussion. Following Rifle Country trends! :D

I guess you could say I'm wondering if anyone else is scratching their head as hard as I am over this cartridge and its design.

R.W.Dale
July 15, 2010, 03:28 AM
actually I disagree that it's not the CALIBER that could be changed to offer the biggest improvement but rather the case length

Lop off 4mm and you'd have opened the door to all kinds of excellent .277 projectiles in much more aerodynamic profiles

The problem with 6mm is it's just not that much different than 5.56 and to the extent of what the SPC was developed for size does matter with regards to the bore


As I see it though the SPC is a cartridge that sold it's soul to the velocity devil at the expense of bullet mass, SD and BC

HorseSoldier
July 15, 2010, 04:17 AM
From an armchair I suppose it's all a puzzler. The round was developed by guys who shoot people for a living and 6.8 was the best performer for what they wanted. I don't think 6mm was even considered as it didn't do anything much better than 5.56.

Matt304
July 15, 2010, 04:53 AM
The problem with 6mm is it's just not that much different than 5.56 and to the extent of what the SPC was developed for size does matter with regards to the bore


It's all about scale, guys. Things need to match, case size and the caliber.

The 6BR is a go-to round for efficient, ballistic performance. Why? Scale, which equates to powder capacity and efficiency. The BR case is small, and thus the caliber needs to be.

Here we have a case not much different in capacity than the BR round. It is just slightly larger than the 223 case, and a bullet slightly larger is what's needed. Instead, they put a bullet mismatched to the case capacity. I guess that's what guys who shoot people for a living do best!

You could easily make this a 600-700+ yard performer with 6mm bullets in this case size. As it stands, you aren't doing much at all with .277 bullets. This case simply does not have the capacity to drive .277 bullets properly.

HorseSoldier
July 15, 2010, 05:05 AM
Optimizing a combat round for 6-700 meter shooting is silly.

Tirod
July 15, 2010, 08:31 AM
Let's see, the SF and AMU worked to make a better, more lethal bullet downrange with the restriction it had to fit the M16 mag well no matter what, and mostly couldn't mess with the bolt face, as it had limits to what size it could accept.

For the military requirement, better range was good, but more foot pounds of force was also a goal, as that is a lot of what lethality is about. A bullet delivering more energy will be more lethal because it has more penetration and creates a bigger cavity which disrupts tissue and blood vessels. More damage means less fight from the recipient, which is the end goal. PAY ATTENTION: the military isn't necessarily looking for Dead Right There. Nice if you can get it, but remember, the worlds Armies already walked away from the .30, 8mm, etc. There is an effective limit to what works altogether in a package.

So, the 5.56 has to have more mass to carry more energy, as it's already on the upper limit in ballistic performance with speed. Making it faster will have quickly diminishing returns, like increasing barrel erosion. We already have to chrome it to keep barrel life up.

In general, bigger is better, but - BUT - only up to a point. You can quickly increase mass to deliver more energy. As the bullet gets more diameter, it also has to accomodate the ogive for streamlining, which makes the bullet seat out further. At that point something has to give - either the case becomes shorter, or the bullet can't get longer.

Add the mysterious art of cartridge case design, which so many of us seem to be uninformed about, and which is a common subject on wildcat forums. The length, diameter, shoulder, and case to neck ratio all have an impact not only on flame propagation, but also the mechanics of automatic feed, especially from magazines. In this specific situation, the M16 has a STRAIGHT magazine well and DOES NOT accommodate tapered cases very well. Highly tapered cases create a bigger problem in this lower trying to feed them, as the properly curved magazine to do it simply hasn't existed.

For those who quickly dismiss lethality as any valid reason in cartridge design, the real truth is that many combat cartridge designer test calibers and bullets on LIVE targets. Shooting pigs has been and continues to be a method to verify the assumptions and calculations that otherwise remain unproven. It would be more than derelict to design a cartridge and never actually shoot a live target until the first soldier is lined up in a GI's sight picture. Pigs are considered a comparable and valid test medium, and are used. When you shoot live targets and see a specific condition is met more often in one caliber combination - powder, case, bullet, and twist as a working team, you don't ignore it for another. The results have been achieved.

Given the existing restrictions - an overall length fixed regardless of whether it's optimum, a straight mag well that limits case taper, balancing bullet diameter and length, and a responsible upper limit on bullet speed, certain combinations get eliminated quickly. One such factor is that extensive military combat studies show the average soldier only shoots out to 400m regardless of the actual effective range of the gun they use. That was discovered when most battle rifles could shoot to 600-800m. Soldiers would not take the shots, and still won't, regardless of the complaints by long range enthusiasts.

With a 400m effective range "limit," it's a waste of effort to design for longer ranges, and compromises the design when used in shorter barrels - like the ISSUE 14.5" M4. No, the military does not have to comply with BATF rules in that regard - they even use 10" barreled weapons. The cartridge chosen would also need to meet the requirements of that use. The government doesn't need multiple rounds of the same caliber optimized for different length barrels, as the use of +P+ submachine gun ammo in the Beretta proved. If a soldier can get the wrong ammo, he will, even if it's not his fault. The cartridge is required to fit in the operating envelope, not the rifle to the cartridge. Those that complain about cheap low powered ammo not cycling their M4gery should take specific note.

Rather than complain about what a caliber is good for, it's probably a better perspective to understand how it got to be as good as it does considering all the dimensional and specific requirements it has to comply with. In that regard, the bigger than 6mm cartridges do a better job in the AR platform, and a lot of shooters already know that. The sales figures are right there, and they are winning.

hammerklavier
July 15, 2010, 11:04 AM
They weren't looking to make a long range gun with great ballistics. They were looking for increased lethality out to 500 yards. The requirement was 500 ft-lb or more energy at 500 yards. They tested a 6mm but it didn't make the cut, perhaps due to the terminal ballistics?

Shawn Dodson
July 15, 2010, 11:33 AM
Here's my frustration. A chance exists to pick any caliber, and .277 is chosen in this day and age? What genius was doing the brainstorming for that cartridge...

Photo of SPC cartridge development:
http://i459.photobucket.com/albums/qq319/DocGKR/SPC_trials.jpg

More info at: http://www.m4carbine.net/showthread.php?t=19936&highlight=Grendel


6.8 mm SPC History and Development (http://demigodllc.com/articles/6.8-mm-spc-cartridge-history-development-hornady-stag-arms-carbine/?p=1)
Cartridge assessment began with the 6mm PPC case, necked up to 6.5mm. The 5th SFG soon discarded the fat PPC case due to poor magazine capacity and insufficient reliability in the M4. Their attention then turned to the .30 Remington case, which is essentially a rimless .30-30 Winchester. Its head and body diameters are larger than 5.56 (0.378 inch), but smaller than 7.62x39mm (0.445 inch). This thoroughly obsolete cartridge was chosen as the parent case because its smaller head diameter (0.422 inch) required less metal to be cut from the bolt head compared to the PPC or 7.62x39mm cases, which improves bolt service life. Several rebated-rim prototypes were created with an SPC body but 5.56's rim (0.378 inch) to utilize unmodified M4 bolts. After trials, it was clear the full-diameter rim helped extraction as compared to the rebated rim design.

Once the case dimensions were tweaked to fit and work in M4-compatible magazines, the project team quickly turned their attention to bore size. Derivative wildcats from 5.56mm to up 7.62mm diameter shooting bullets from 90 to 140 grains were subjected to a battery of tests, and a sweet spot emerged. The 6.5mm bullets showed the best accuracy and the 7mm bullets were the most destructive, but the 0.277-inch bullets showed almost the same accuracy and trajectory as the 6.5mm and almost the terminal performance of the 7mm. When necked down to 0.277-inch and shooting 115-grain bullets, it provided the best combination of combat accuracy, reliability and terminal performance for up to 500 meter engagements. This cartridge was deemed 6.8 Remington Special Purpose Cartridge (SPC), because 0.277 inch is 6.8mm in metric and .30 Remington provided the parent case.

Matt304
July 15, 2010, 01:26 PM
Thanks for the history, guys.

That's an eye opener! I was not sure that this round had the amount of homework done that it did, with all of the different calibers being used. But it sounds like they did do their homework on finding the caliber for their needs.

I personally would not be shooting live targets in combat. So if it were me, I still would be chambering the wildcat, 6mm version for a paper-puncher.

Dionysusigma
July 15, 2010, 02:42 PM
I personally would not be shooting live targets in combat. http://graphics8.nytimes.com/images/2007/10/15/nyregion/15zombie.span.jpg


:D

Matt304
July 15, 2010, 04:38 PM
Good play of my words! :D

You know what I meant!

I have defense firearms covered and ready. From now on, when I buy evil black tac rifles, I want them to, when possible, be able to hang off my 500 yard bench. ;) Since I reload everything anyways, I would prefer to use a caliber with bullets I like.

Anyways, I just wanted to post what I thought about the 6.8mm and hear some other views like I have here.

...Thread tapers to an end.

mshootnit
July 15, 2010, 08:22 PM
In fact I started a thread with this title awhile back. Totally agree that 6mm in that case would be a good improvement, while finding something that would get the 100 grain bullet going 3200 or so while being compact and logistically reasonable would be very lethal. I also like the 6mm OCC.
6mm's are much better than 22's (more so than most understand)

HB
July 15, 2010, 09:25 PM
I agree with the 6mm fans... It seems if you could get it going fast enough, with match style 105 grain bullets it would have enough velocity to reach out and touch somebody out to 600m and still have plently of tumbling effect out to that distance. 6mm Hagar anybody? (Which i believe is based on the .30 rem case as is the 6.8?)

amprecon
July 15, 2010, 09:25 PM
There is way too much disparagement about the 6.8 spc and I try to figure out why. I think maybe because it was touted as the 5.56 replacement. Many AR fans may of had other ideas of what should replace the 5.56, maybe AR fans didn't want any change at all. Maybe it wasn't AR fans shouting about it the most after all. Who knows, but I don't think I've read so many derogatory remarks about a particular rifle caliber ever.
Pistol calibers?....sure, there are diehards in almost every pistol caliber camp, but rifle calibers...? Not so much, at least not until the 6.8 spc was introduced.
All I mostly hear is that it sucks and the 6.5 Grendel is better. It's all rather immature.
I went 6.8 because I became interested in piston AR design rifles in a more effective caliber than 5.56. After reading about the research and development of the 6.8 and of many successful hunters using it, I was sold. Albeit I didn't go the piston route as they were more expensive, I took a leap of faith and went with a RRA DI rifle.
The AR platform was readily and apparently moderately easy to modify to accept it, the recoil is sublime, it is accurate and apparently quite effective within its limitations.
If some people don't like it.......well, I'm fine with that.

Tirod
July 15, 2010, 11:39 PM
As Barnes and others make purpose built bullets for the 6.8, dimensions and the ogive are being tweaked to improve ballistic coefficient, which keeps creeping up as new bullets are released.

6.8 is becoming it's own bullet, not just another .277. And as loads are tweaked, users are reporting getting as much as 2970 fps from a 12" barrel, chronographed. Apparently you can push an 85 grain bullet with a military load and keep velocity nearly the same as the 5.56, from an 8" shorter barrel.

Matt304
July 16, 2010, 01:03 AM
amprecon said:

It's all rather immature.

Constructive thinking is immature? I'm sorry that it doesn't appeal to you, but we all have our different ways of communicating our constructive thinking. It's all for the better, really. Without it, we would just accept everything that a manufacturer hands us, there would be no wildcats, and there would be no progression in the world of accuracy and what is possible.

I feel like when I think about calibers anymore, I think more "ballistically" I guess you could say than I ever used to. I used to be a fairly common shooter. I was not very intimate with rifles and ammo, and bought my ammo from a hardware store. Back then, I used to think the 270 Win was the best long range cartridge that no one ever realized. It was big, sleek, and shot fast. That was because I owned one, and didn't have a true performing long range cartridge. That was also before I bought a 6.5-284.

Once I started getting into reloading, and examining the science of shooting a lot more, I realized that I previously had no idea how things really worked. I found that less recoil went a long way on the bench. I found that better bullets gave much better groups, and multiplied those abilities at extended ranges. I guess you could say that I became modernized with the bench, and from now on when I look at things, I have a hard time seeing things through the eyes of people who create rounds for self defense. I always find a way to envision the cartridges in an optimal sense, as in, what could they do if they were tweaked for shooting, instead of shooting + lethality. I find myself ending up wondering if a better shooting bullet might actually make more sense for most people than a bullet with more lethality compared against it.

One of the problems I have trouble with is knowing that the people who own these 6.8s, taking these rifles to the ranges, don't absolutely need the same requirements as the people those rounds were designed for. The cartridge was designed for human targets. Though it is possible we may someday need to use our firearms to dispatch human targets, we don't do that on a regular basis. Some people like to dress up and pretend they do, but the cold hard reality is that they don't. They are still shooting paper on a regular basis.

So I ask myself. Why do you want to jump on the bandwagon with the people who designed this round for something different than YOU use it for? Why wouldn't you want to tweak this caliber back to an optimal shooting caliber? It was admitted above in the research that the developers saw the smaller bullets could shoot better.

So I ask, are you using the 6.8SPC for what it was designed?

Would your situation most likely follow the average battlefield situation, even if you had to use it for the type of work it was designed for in the battlefield?

It was stated that the average soldier will not take shots past a few hundred yards. Well, if SHTF, I would like to believe that I am not the average soldier. I promise you this; I would take those 600 yard shots!

What it boils down to is realizing that I am not the person the 6.8SPC was designed to meet a criteria for. If it is me who needs it, it is most likely a 6 SPC that will work better. I like to believe that most of the people that own a 6.8SPC right now are shooters closer to resembling me than resembling a soldier. They've all got the wrong caliber. ;)

HB
July 16, 2010, 02:22 AM
I like to believe that most of the people that own a 6.8SPC right now are shooters closer to resembling me than resembling a soldier. They've all got the wrong caliber

Now thats what I'm talking about! I would think a 6mm that fits in an AR would be an ideal deer round because you can use an expanding bullet. I suppose if you are stuck with a OTM or FMJ, then 6.8 makes a little more sense... To me, its still just an improved 7.62x39


HB

Bigfoot
July 16, 2010, 02:32 AM
The 30/06 was designed as a military cartridge too. I'd better not take mine hunting anymore.

Matt304
July 16, 2010, 02:52 AM
The 30/06 was designed as a military cartridge too. I'd better not take mine hunting anymore.

Quit being a noggin head. :rolleyes:

Instead of adding something constructive, you input some little comment that doesn't even somewhat resemble any form of argument depicted in the thread. Perfect.

Abel
July 16, 2010, 08:03 AM
It would have been a winner if it was marketed correctly. If it was called a short range deer/hog buster and repackaged as the 270 Bantam, it might become a winner, the new 30-30. Its a constant reinvention of the wheel, I know.

longdayjake
July 16, 2010, 09:02 AM
One thing that I can definately say for the 6.8 is that it does appear to reach its maximum velocity in a very short amount of barrel. For those going inside of buildings to clear out an enemy that is a great thing. That is what it was designed for. However, the war in Afganistan has proven to be a different kind of war. Everything you see or read about Afganistan is that our soldiers are being out gunned with longer range cartridges. It appears as though there is a need for something that can reach out there.

Optimizing a combat round for 6-700 meter shooting is silly.

Tell that to the guys in the mountains of Afganistan. My point here is not to say that the 6.8 is crap, but that there is indeed a need for a cartridge that can reach out there when needed. Every war is different and should not be held to the same standard as a cartridge that was designed to fight in dense jungles of Vietnam where you most likely couldn't see 50 yards in front of you let alone 400-600 yards. It is ridiculous to me that the military can see a need for a new truck (MRAP) in Iraq, but it doesn't see a need for longer range weapons in Afganistan. Imagine how many troops could be supplied with an m14 or (heaven forbid) a 6.5 Grendel for the cost of one MRAP. In Iraq 10,000 MRAPs were ordered at a cost of about $500,000 each. So, we are okay with our troops getting out gunned in an actual battle as long as they can ride to the battle in style.

The 6.8 is great indoors. Go outside and the OP has got a point.

Al Thompson
July 16, 2010, 10:41 AM
I still would be chambering the wildcat, 6mm version for a paper-puncher.

6x47 is a very handy cartridge. Cheap too. :)

Longdayjake, I'm not HorseSoldier, but I think I follow his logic. Historically, grunts fight at sub 300m. The Germans noted this even during the Russian campaigns. The skill needed to hit 500m and furthur is pretty training intensive and the equipment (DM rifles) is what should be optimized for the longer ranges.

In a perfect world, every 11B or 0311 should be effective to a klick with his individual rifle, but that ain't going to happen. As it is, every good commander wants his guys to be deadly out to the infantryman's half kilometer. :)

longdayjake
July 17, 2010, 06:12 PM
I'm not HorseSoldier, but I think I follow his logic. Historically, grunts fight at sub 300m. The Germans noted this even during the Russian campaigns. The skill needed to hit 500m and furthur is pretty training intensive and the equipment (DM rifles) is what should be optimized for the longer ranges.


I will not argue that most battles occur within 300 meters. What my point was supposed to convey was that our troops are being killed by under trained religious fanatics because we don't have the tools to shoot back. We are arguably the richest country in the world and we can't foot the bill for more .308 shooting marksmen? If they can shoot and kill us at long distance then we sure as hell should be shooting back. My point is that we can afford the training and the weapons, but for some reason we still depend on an underpowered cartridge. Why keep with the .223 when something else exists that can do both close and long range from the same platform?

Hows that for arm chair commando?

Mags
July 17, 2010, 06:25 PM
I think marketing is the true shortcoming of the 6.8. If you could go into Wal-Mart or any other major sporting store and pick up a box of ammo for 12.50 or less per 20 then the 6.8 may catch on. But with only 3 mainstream ammo manufacturers and 2 of them being high end companies the 6.8 is just too expensive compared to other options for civies in the AR platform such as the 7.62x39 and the origimal chambering in 5.56. If you are going to have to look high and low for ammo and then pay a mint you might as well get yourself a 6.5 Grendel,458 SOCOM, or 50 Beowulf.

I am actually kind of bitter that none of the cartridges designed for the AR have taken off into mainstream distribution. I would love to get a different caliber upper for my ARs but due to marketing it is somwhat pricey to take full advantage of the ARs modularity.

What is even stranger is the propietary calibers of the AR10 design are quite popular perhaps due to the fact they were not designed around the parameters of the AR10 but have been rather popular calibers before the AR10 rose to common usage. Calibers such as the 243 Win, 7mm-08, and 338 Federal have only became more popular with the modular capability of the AR10 platform.

Now if the military were to adapt any of the available caliber options other than the 5.56 in the AR15 platform for general mass issue then whatever caliber selected would rise to popularity. But only if it is a fully adopted and not just for special ops use. I just wish they had went with the 6.8 so I would buy myself a nice upper.

Jerry M
July 19, 2010, 06:07 PM
Check out this site, your prayers have been answered.

http://www.6mmar.com/

Good luck

Jerry

Jaws
July 19, 2010, 07:09 PM
What genius was doing the brainstorming for that cartridge...

It was someone much more capable than you think. He did, in my opinion, the best you gould get, out of the cards he was dealt.

in a perfect world, for the same aplication, his other cartridge (7x46mmUIAC) would be as close to perfect as you could get with today's technology.

7.62x39mm case extended to 46mm, necked down to 7mm pushing a 130gr, .411BC bullet at 2650fps out of 16 inch barrel.

Ratdog68
July 19, 2010, 07:28 PM
The 6.8 is the second most purchased AR being made (at present). Thankfully... today's rendition of the chambering/barrel specs is light years better than the pitiful thing that Remington registered with SAAMI. Remington fell flat on it's face with that offering. Instead of following the progress that's been made to overcome what it was and updating it... it tucked it's green tale between it's legs, discontinued what could be a great model 700 offering, and continues to offer anemic loads in their large primered brass that isn't good for much more than a few reloads.

Am I a Remington hater? No, I own six Remington rifles, three center fire and three rimfire. I'm a big fan of the 700. But, from appearances, their R&D team (in it's current form) sucks.

Given the obstacles from the beginning of the round? The 6.8 has become a fine cartridge, and capable hunting round... in spite of Remington.

Matt304
July 19, 2010, 07:40 PM
today's rendition of the chambering/barrel specs is light years better than the pitiful thing that Remington registered with SAAMI. Remington fell flat on it's face with that offering. Instead of following the progress that's been made to overcome what it was and updating it... it tucked it's green tale between it's legs, discontinued what could be a great model 700 offering, and continues to offer anemic loads in their large primered brass that isn't good for much more than a few reloads.

Can you elaborate on what exactly you are talking about?

I would like to know.

Hammerhead6814
July 19, 2010, 08:03 PM
Here's the solution to any 5.56 vs 6.8 vs 6.5 vs whatever debate for the AR platform.

Remove Ar-15 upper receiver. Remove AR-15 lower receiver. Add AR-10 lower receiver. Add AR-10 upper receiver. There, that answers any questions about caliber in the AR platform. The only thing better would be a .30-06 or 7mm Mauser AR. One can dream right?

Maverick223
July 19, 2010, 08:36 PM
As I see it though the SPC is a cartridge that sold it's soul to the velocity devil at the expense of bullet mass, SD and BC+1, that is my qualms with the 6.8SPC. IMO they should have went with 6.5mm or 7mm. Using .277cal just doesn't make sense to me, when there are such good choices only a few hundredths of an inch away (FWIW 7mm is only 7 thousands of an inch difference, but the bullets offered afford much better ballistic qualities). It seems to me that the best choices are a necked up 5.56NATO (the 6.5MPC or even a 6x47mm), the 6.5Grendel, or a wildcat 6.8SPC (necked to 6.5mm or 7mm). I would buy any of the aforementioned right now if offered in the right platform.

:)

Ratdog68
July 19, 2010, 08:49 PM
Can you elaborate on what exactly you are talking about?

I would like to know.
You can read up on the whole tale with varied stickied threads on 68forums.com. Basically, the 6.8 SPC SAAMI spec chamber was found to generate excessive pressure, blowing primers (even out of Remington factory loads, which are the weakest of the current offerings), and incapable of delivering the terminal ballistics that were being strived for. The Remington 700 offering is a prime example of that version.

A group of people who believed in the potential of the cartridge started to do their homework and did some testing. The leade was changed to what is referred to as 6.8 SPC II and dramatic improvements were achieved with the resulting drop in chamber pressures. Further testing resulted in the determination that since the caliber is limited by the capacity of the magazine's fit in an AR-15 mag well... smaller projectiles were allowing the use of more powder capacity, netting even more velocity (in conjunction with the lower chamber pressures of the new chamber spec). The lighter/smaller bullets showed better velocity with the further change to slower twist rates than the original 1:10 twist barrels of the .270. The change to a different rifling with a land/groove ratio of 70/30% netted a bit more muzzle velocity with the resultant decrease in friction applied to the bullet as it travelled down the barrel.

So... with about five years' worth of efforts put into the caliber... only a couple of rifle manufacturers are still making their offerings with the SAAMI spec'd chamber and original 1:10 barrel/rifling combos. The round, in a correct/up to date chamber/barrel combo will now perform well at close to 3000fps velocities. And, with the newly introduced Barnes 95gr TTSX which was designed specifically for the 6.8... which was designed to open effectively to speeds of 1600fps... the 6.8 SPC II is now capable of taking game to 450yds. It's become a one shot DRT hog killer (provided the shooter does his part), and I know of one individual who took a black bear with two rounds of the Barnes 110 TSX out of his 6.8 AR platform. It's also quite good at dropping deer. SSA offers two types of loads for the 6.8 SPC, "Commercial" for the old spec chamber/barrel combo and "Tactical" loads for the up to date 6.8 SPC II spec'd chamber/barrel rifles.

Simply put... it's like comparing the .223 Remington with the 5.56 NATO chambered rifles. The 5.56 will shoot both, but don't try the hotter 5.56 in your .223.

I've been learning a lot as I haunt that forum. I hadn't even heard of the 6.8 until about February of this year. It sparked my interest and I started digging/reading and asking. Good group of folks over on that forum. To get the best equipment the caliber has available to it... I'd stick with the vendors supporting that forum. They've been the ones to do the research/testing and are keeping themselves on the cutting edge for this caliber. ARPerformance, Bison Armory, Wilson Combat, Black Hole Weaponery, Noveske seem to be the ones leading the charge on the best specs for chamber/barrel product. SSA has been the most active with keeping the ammo up to date with the cartidge's evolution/improvement. Hornady is probably a close second. Remington's large rifle primer pockets seem to be loosening up long before SSA or Hornady's brass... so, even though Remington's brass is cheaper (up front), the longevity of the SSA/Hornady brass nets more value in the end. You'll also want to compare the advertised velocities of the ammo manufacturers. Remington's failed to keep up with the progress.

Shade
July 19, 2010, 09:40 PM
One thing I would like to add to this that others have said but cannot be stated enough is that this is not meant to be the "ultimate round". It's built to give the ar15 more lethality within it's designed range with a shorter barrel, while maintaining low recoil and normal magazine capacity. Thats it.

The ar15 is an assault rifle not a long range sniper rifle. It's seems a lot of people want the 6.8 to do the job of the 5.56 and the 308. The 308 works awesome at long ranges, has for a long time and will continue for a long time.

The 5.56 was designed for longer barreled rifles in which it works consistently effective, in short barreled rifles, however, it seems to have limited lethality. The 6.8 is designed specifically to address this problem.

amprecon
July 19, 2010, 11:56 PM
Quote:
amprecon said:

It's all rather immature.

I don't mind fans of each side touting the attributes of their favorite caliber, what I find immature is when one side poo poo's the other just because....that is immature.

Al Mack 1
July 20, 2010, 12:59 AM
I don't remember where I heard or read this. But because of the royalties Grendel wanted for the use of there 6.5. The 6.8 was designed. Simple as that.

Sheepdog1968
July 20, 2010, 02:19 AM
I'm of the opinion that we have all the cartridges we need and that we don't need any new ones. I tend to be very conservative and don't adopt new cartridges readily. As for rifles, is the 5.56 is under powered for the application, I'd look at either the 7.62x39 or 7.62x51 long before I'd go with something else. Even if you showed me data, I'd still lean towards well established rounds. I suspect there are many like me who think that way. Rather than bullet performance, I think the resistance to a new caliber is the biggest problem.

Ratdog68
July 20, 2010, 12:19 PM
I'm of the opinion that we have all the cartridges we need and that we don't need any new ones. I tend to be very conservative and don't adopt new cartridges readily. As for rifles, is the 5.56 is under powered for the application, I'd look at either the 7.62x39 or 7.62x51 long before I'd go with something else. Even if you showed me data, I'd still lean towards well established rounds. I suspect there are many like me who think that way. Rather than bullet performance, I think the resistance to a new caliber is the biggest problem.
If you've priced the AR-10 platform lately... you'll understand the following of better performing calibers for the AR-15 platform. There's also a fair load carrying difference, both for the weapon as well as for the rounds. Weapon weight being the more important consideration for the hunter, ammo weight/capacity also being of concern for the soldier.

Maverick223
July 20, 2010, 12:42 PM
If you've priced the AR-10 platform lately... you'll understand the following of better performing calibers for the AR-15 platform. There's also a fair load carrying difference, both for the weapon as well as for the rounds.+1; the AR-10, whilst more powerful, is also larger, heavier, more costly, and doesn't have the universal parts that the AR-15 affords. In many ways the AR-15 with a larger cartridge is superior to its big brother.

:)

PedalBiker
July 20, 2010, 01:12 PM
I think it could be a winner as is. I'd like to see a 7615 pump in 6.8spc from Remington. I'm considering a Ruger mini 6.8, but I don't like semiautos.

Frankly, though, Hornady's Leverevolution 30-30 makes brings the 30-30 up to 6.8SPC territory and a Marlin 336 would be just as handy as a 7615 pump.

Ratdog68
July 20, 2010, 01:28 PM
I think it could be a winner as is. I'd like to see a 7615 pump in 6.8spc from Remington. I'm considering a Ruger mini 6.8, but I don't like semiautos.

Frankly, though, Hornady's Leverevolution 30-30 makes brings the 30-30 up to 6.8SPC territory and a Marlin 336 would be just as handy as a 7615 pump.
At present, Ruger does not use the SPC II chambering, and reaming it would allow you more choices in ammo to use in it.

jmorris
July 20, 2010, 03:34 PM
6.8mm is kind of like owning a Saab, no good reason other than to be different. Less than 8 thousandths of an inch difference between it and a 7mm. Talk about apples to apples….

Ratdog68
July 20, 2010, 04:15 PM
I take exception to that... I would never own a Saab. :D

Lloyd Smale
July 21, 2010, 06:49 AM
me i would have liked to see a 257spc. give a guy an opition to shoot 87s or 100s for normal work and 120 partitions or ball when you need penetration.

Sheepdog1968
July 21, 2010, 03:51 PM
If you've priced the AR-10 platform lately... you'll understand the following of better performing calibers for the AR-15 platform. There's also a fair load carrying difference, both for the weapon as well as for the rounds. Weapon weight being the more important consideration for the hunter, ammo weight/capacity also being of concern for the soldier.
Your logic is reasonable. It's just not the way I'd want to go personally. Yes, the AR10 and M14's are definately heavier. Having said that, if the 5.56x45 isn't adequate for the needs, I'd be inclined to switch to the 7.62x39 before I'd go to the 6.8 SPC.

I remember once reading a Loui Awerbuck article in SWAT and I there was a lot of talk about some new cartridge. He commented something to the effect, "does anyone remember the 41 magnum?"

When I think of the 6.8, I think of the following cartridges (yes, they're pistol ones so it's not necessarily a fair comparison): 45 GAP, 10 mm, 41 magnum, and dare I say the 357 Sig. Yes you can find them, but they aren't main stream and going to have as steep a discount. Same is true in my mind of the 6.8 round. I have no doubts its better the 5.56, however they are other rounds out there that have prooven over time that they are unlikely to be a fad or flash in the pan.

Ratdog68
July 22, 2010, 12:12 AM
Your logic is reasonable. It's just not the way I'd want to go personally. Yes, the AR10 and M14's are definately heavier. Having said that, if the 5.56x45 isn't adequate for the needs, I'd be inclined to switch to the 7.62x39 before I'd go to the 6.8 SPC.

I remember once reading a Loui Awerbuck article in SWAT and I there was a lot of talk about some new cartridge. He commented something to the effect, "does anyone remember the 41 magnum?"

When I think of the 6.8, I think of the following cartridges (yes, they're pistol ones so it's not necessarily a fair comparison): 45 GAP, 10 mm, 41 magnum, and dare I say the 357 Sig. Yes you can find them, but they aren't main stream and going to have as steep a discount. Same is true in my mind of the 6.8 round. I have no doubts its better the 5.56, however they are other rounds out there that have prooven over time that they are unlikely to be a fad or flash in the pan.
'Cept... the 6.8 SPC is the second most purchased caliber in the AR platform. (Much to the 6.5 Grumble's dismay). :D

Mr. T
July 22, 2010, 01:41 AM
I still wonder why, if knock down power and punching capabilities are the Holy Grail for the military, why they don't go to the .308 or 30.06 caliber. The 30.06 round did the job in WWII. If we want our guys to shoot through cars or even walls of buildings, the 30.06 did that in spades during WWII. And before someone mentions round carrying capability please answer why I should shoot someone two or three times instead of just once to put them out of the fight.

Regen
July 22, 2010, 10:39 AM
round carrying capability please answer why I should shoot someone two or three times instead of just once to put them out of the fight.
Because most rounds don't hit an enemy soldier. Often, keeping an enemy's head down so that you can maneuver is more important than a one stop shot.

Mags
July 22, 2010, 10:43 AM
And before someone mentions round carrying capability please answer why I should shoot someone two or three times instead of just once to put them out of the fight. You are going to put more than one in a BG, you are not going to shoot once and wait and see what happens. You are going to shoot until the threat stops.

benEzra
July 22, 2010, 12:12 PM
I will not argue that most battles occur within 300 meters. What my point was supposed to convey was that our troops are being killed by under trained religious fanatics because we don't have the tools to shoot back. We are arguably the richest country in the world and we can't foot the bill for more .308 shooting marksmen? If they can shoot and kill us at long distance then we sure as hell should be shooting back.
We already outrange them; the bad guys aren't hanging back because they outrange our guys, but because if they get any closer they will completely lose any chance to E&E. This is not a 5.56x45mm shortcoming, it's a function of distance, area, and response time.

And generally speaking, if our guys need to engage an enemy force at 600+ meters, they use the appropriate weapons---which aren't, generally speaking, small arms.

My point is that we can afford the training and the weapons, but for some reason we still depend on an underpowered cartridge. Why keep with the .223 when something else exists that can do both close and long range from the same platform?
Because switching to .308 from .223 goes against the shortcomings of 7.62x51mm that led to the switch to 5.56x45mm in the first place.

Soldiers are already maxed out as far as weight they can carry. If you switch to a heavier rifle with heavier magazines that shoots twice-as-heavy ammo, the only way to offset that weight is to carry less ammo and fewer magazines---and the heavier 7.62x51 is slower on target and slower in followup shots than 5.56x45mm. All of the above hurts you in the vast majority of real-world engagements (those at 1 to 200 meters), while not really helping you in the rare long-range engagements beyond 600m because most of those don't depend on small arms in the first place.

HorseSoldier
July 22, 2010, 12:22 PM
+1 -- the extreme ranges the Taliban are using these days are not making for effective ambushes, but that's the only range where they have a chance to survive the contact. They did the same thing with the Soviets -- most muj ambushes were done at such long range Soviet armor/mech units often didn't e even know they'd been ambushed and rolled right through "kill zones" without response. We're hitting them with the right mix of equipment and such, and the usual internet navel gazing about calibers and weapons is as off base as such things usually are.

henschman
November 15, 2010, 01:27 AM
The average infantryman doesn't take shots beyond 3 or 400m because he is not confident in his maximum effective range and his ability to hit the target at distance. That is because he is not taught the fundamentals of rifle marksmanship and distance shooting.

It takes a bunch of time and specialized training to teach people to shoot effectively past BSZ range? That's news to me. We do a pretty good job of teaching people to shoot the Rifleman's Quarter Mile in just one weekend at Appleseed, and an even better job teaching it at our week-long Rifleman Boot Camps. If we can turn a bunch of civvies into Rifleman in one week, the military ought to be able to as well. Heck, we've even done it for the military... Appleseed has trained several Army units, and all of them went away with a vastly increased maximum effective range and confidence in their ability to hit the target... not with an expensive new rifle or ammunition or anything... just the proper fundamentals of rifle marksmanship. That and a GI web sling.

That is probably the easiest single thing we could do to improve effectiveness at distance... teach proper rifle marksmanship. Of course it would be better if we had a more effective caliber... I like the idea of a 6.5-7mm round out of a .308-sized case or so. Basically like the .276 Pedersen that we almost switched to back in the 1920s (what the M-1 was originally designed for).

Maybe a round like that out of a bullpup would be the way to go. That way it would be compact and light enough for close quarters fighting, but could have a long enough barrel to work for long range work. Something along the lines of the Kel Tec RFB would be nice, but with a 22" barrel or so. Carbine-like dimensions for close quarters work, but with a round that is flatter shooting and with a longer max effective range than the 7.62 NATO.

HorseSoldier
November 15, 2010, 01:42 AM
The problem with engagements past 3-400 meters isn't that troops lack confidence in their abilities, it's that on a two way range with the other guy in camouflage or a drab colored man dress it's a trick to even detect the other guy. Then it's another trick to positively ID him as hostile, and a third trick to get your shot lined up and take it. The bad has to do one trick -- get back behind cover before you shoot him.

That's why there just isn't any support for the notion that long range marksmanship ever paid big dividends after people started dressing in various shades of mud colored clothing and stopped marching towards the enemy in open order trying to stop bullets. It didn't work well by late WW1 and hasn't started working better.

Even trained snipers, with much better optics, make their money out past 400 meters either striking from ambush at static bad guys or correcting off their first round misses. Both the post-9/11 shots that edged out Hathcock's record from Vietnam featured misses before hits, for instance.

GunTech
November 15, 2010, 08:57 AM
The idea of smallarms engagements beyond 300 yards is a rifle range mentality that has nothing to do with the realities of modern infantry combat. As already noted, hit probability at 500 yards drop to nil, and 90% of all small arms fire takes place at 300 yards or less. This has little or nothing to do with marksmanship, but rather the ability to see the target and intervening terrain. Unlike wars in the 19th and early 20th century, modern fighters are taught the use of cover and concealment, the use of camouflage and fire and maneuver. Even the most experience, highly trained shooter cannot hit a target he cannot see.

Volume of fire has value not just for fixing an enemy's position, but also to make return fire less effective even at the cost of ammunition. All those 'wasted' round have led to a reduction in friendly casualties. Better to trade bullets for wounded or dead soldiers, IMO.

BTW, the average range of engagement in the ETO in WWII, where the 30-06 was the standard round, was 75 yards. Marines in Iraq are averaging 50 yards.

Longer ranges are really the realm of intermediate weapon like mortars and other area effect weapons. Point weapon like rifles are to easy to render ineffective by cover and distance.

This thread may be of interest: http://www.thehighroad.us/showthread.php?t=327113

The 6.8, like every other round developed as an answer to the 5.56, is a compromise limited by what can fit in an M16 and be controllable under full auto fire. The latter is something frequently missed by civilian shooters who've never fired a select fire rifle and don't appreciate how small changes in recoil are amplified when more than one round goes down range per pull of the trigger.

The goal was better lethality at combat ranges. There is a lot of room to argue that adoption of the M855 over the M193 reduced effectiveness of the M16 platform. It seems to make little sense when one considered that the M855 was adopted in part because it offered better long range potential than the M193, while the Army's own studies indicated that small arms aren't effective at longer range and that the effectiveness of small caliber projectiles require high velocities to be effective.

In particular, the 5.56 has been particularly effective due to it tendency to fragment, and this phenomenon requires a velocity of around 2800 fps IIRC. Adopting of the M855 reduced initial velocity of the 5.56 by about 300 fps, reducing the fragmentation range by a good measure in return for longer effective range that wasn't needed.

There is a valid argument for a round optimized for very short barrels which rob the 5.56 of its necessary velocity. But there is an equally valid argument for staying with rifles and preserving carbine length weapon for where they are really necessary.

Tirod
November 15, 2010, 10:03 AM
in the hands of a soldier in the squad. From 25m to 25 miles, it has a series of escalating choices and resources with which to engage the enemy.

The major mistake in discussing what the Army should issue as a weapon to the soldier is thinking that will be the only one on the battlefield, then complaining the enemy gets to use old Enfields in .303, or Russian .50 calibers. It shows a complete lack of familiarity with what the unit may have in organic firepower.

My old Reserve unit is currently deployed in Afghanistan, once again doing convoy security and area control. If they are equipped like the MTOE says, then they have individual 5.56 and 9MM weapons, an MG on the HMMV, MK17s, etc. The average MP squad actually has more firepower than the Infantry. Like as not there will be BN designated assets along for the ride, including a SDM with an M14, and a .50 up on a truck. We haven't even mentioned artillery or air cover when needed.

All that for the primary threat, which is an IED on the road. The long range shooter in the hills is way up there because they don't dare get any closer. They make points if they can harass a convoy, we only count dead bodies, the contest is pretty unequal and they know it.

Please don't bring a high precision long range school of thought into what is basically a response to chaos. As was said, when someone is shooting back and doing their best to remain covered and concealed, the use of a carbine or rifle gets a lot harder. Try having your buddies hiding the targets behind bushes, gaps in a berm, or back in a hut. Find those targets and accurately shoot them. Better yet, walk a mile between targets. Sniper matches are held like that.

I'll tell you up front you can't shoot a target you can't see. It's why we have weapons that cover a general area, like a machine gun or automatic grenade launcher. Put 8 rounds or a grenade in that target, you get a lot more result than firing the 5.56, regardless of optics.

Real combat stacks the cards against the easy shot. Concepts of ballistics outside of 500m don't apply to individual weapons, because the percentage of shots dwindles to zero. It's not like on a sunny Saturday afternoon, it's Thursday morning at O'dark thirty, and you don't get any weekends off.

If you prefer a particular bullet size and shape for the statistics it has on paper, and how they might optimize your shooting situation, go right ahead and use it. However, please don't think that combat use of a firearm has any connection to it at all - unless you are shooting live targets hiding in the environment.

That is why so many choose the 6.8SPCII. It's NOT a paper punching caliber, complaining about it is exactly what is wrong. The SF and AMU never intended it for lazy afternoons at the range.

GunTech
November 15, 2010, 10:20 AM
I'll tell you up front you can't shoot a target you can't see. It's why we have weapons that cover a general area, like a machine gun or automatic grenade launcher. Put 8 rounds or a grenade in that target, you get a lot more result than firing the 5.56, regardless of optics.

Which is exactly why the Army is looking at the smart grenade launcher (XM-25) as the eventual replacement for the rifle, first as a specialist weapon, but if cost and weight allow, it may become the next generation of infantry weapon.

Maverick223
November 15, 2010, 12:29 PM
Adopting of the M855 reduced initial velocity of the 5.56 by about 300 fps, reducing the fragmentation range by a good measure in return for longer effective range that wasn't needed.I agree, and while my opinion isn't particularly valid (no combat experience), I think it was taking a step backwards. OTOH the same cannot be said for the new 77gr. OTM, and the new "SOST" round looks promising as well.

Either way, I don't believe the decision to move from the 5.56NATO to something larger (or smaller for that matter) will be anything made with haste...nor should it.

:)

GunTech
November 15, 2010, 05:44 PM
There is really only one good reason for moving up caliber and that is logistics. A correctly designed intermediate round could theoretically replace both the 7.62x51 and the 5.56x45 with a single round. Such a round would be a compromise as well, with more recoil than the 5.56x45 and less hitting power than the 7.62x51 at shorter ranges. High BC bullets in 6.5 and 7mm can best the current M80 ball at moderate to long range.

That being said, the current system works so there's not much impetus for something else.

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