posted 12-31-2003 04:46            

STAN2,

The Russians already produce 7.62 x 54 mm sniper ammunition that fragments similar to U.S. M852 and M118LR.

Lets review a couple of things.

What combat mission needs did the end-users in the SOF community identify for the SPC? At the bottom of the first page of this discussion, ”Stan”, an experienced U.S. special warfare veteran known to both Pat Rogers and me, offered the following cogent comments based on his experience, which includes extensive time overseas in combat zones the past two years: “The consensus of trigger pullers I know, want a user friendly platform, and to be able to smack from 0-400. Four plus, give me a MK11 or better a WinMag.”

The folks who conceived the 6.8 x 43 mm SPC had to meet a number of requirements, including: ensure easy retrofitting to current SOF 5.56 mm rifles (Mk12, M4) and adaptability to future systems (XM8, SCAR), keep chamber pressures at or below current 5.56 mm NATO levels, use M4/M16 magazine dimensions and provide at least a 25 round capacity, offer 1 MOA accuracy out to at least 500 yards when fired from 12.5" to 16" barrels, offer complete reliability in a variety of environmental conditions, function without failures in both full-auto and semi-auto firing, offer recoil and controllability comparable to 5.56 mm and 7.62x39mm, and offer improved incapacitation effects within established JAG guidelines for lawful land warfare use.

The guys at AMU who designed the SPC are obviously very experienced with match, as well as long range shooting; they initially experimented with using 7.62x39mm/7.62x45mm (Czech), and PPC based cartridges for this project. Unfortunately, that path did meet the project requirements in several areas. For one example, look at AK or 7.62x39 mm AR15 mags used for cartridges such as the 7.62x39/45 & PPC’s—they are substantially more curved and obviously of different dimensions than a standard M4/M16 mag……just one of many reasons why the SPC ended up in it’s current form. As previously mentioned, projectiles from 6 mm to 7.62 mm were tested, in multiple weights from 90 gr to 140 gr, using several different bullet types. Also keep in mind that the 6.8 mm SPC is intended for use with and has been tested in 12” to 16” barrel combat rifles, not 24” barrel match rifles.

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posted 12-31-2003 07:52               

quote:

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The JAG's ruling permits match hollowpoints to be used against both lawful and unlawful combatants. If other nations fear that the U.S. will use such bullets against their soldiers, then Russia, China, India, and others might begin producing fragmenting bullets for their own small arms. Sooner or later, some will end up being used against our troops. This would result in a higher -- perhaps much higher -- percentage of U.S. troops incurring lethal, amputating, and/or mutilating wounds.

We cannot count on this "performance edge" staying solely on our side. So I ask you, is the gain really worth the potential loss?

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I disagree with this argument. We have been using fragmenting bullets (i.e., M193) for forty years now. IIRC, the thirty year old Soviet 5.45x39mm load fragments similar to M193 ball. In fact, I believe some versions of the old 7.62x39mm (East German?) also fragment violently. My point is that fragmenting bullets are already or have been in use by both the U.S. and its enemies for several decades. That is the basis of the JAG ruling--if the terminal performance is the same or similar, the construction of the bullet (FMJ vs. OTM Match) makes no difference.

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Alfadog
NRA Life Member

posted 12-31-2003 09:19               

quote:

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Originally posted by Alfadog:
....IIRC, the thirty year old Soviet 5.45x39mm load fragments similar to M193 ball. ....

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Alfadog,
Where have you seen test showing 5.45 Russian fragmenting? Can you post a link or cite a study?

What few papers I've seen on the round indicate it does not fragment; but it does swap ends a couple of times.

Best info I've found on the 5.45x39:
http://www.btammolabs.com/fackler/ak74_wounding_potential.pdf

posted 12-31-2003 09:50               

Maybe I missed it in this thread, but can someone provide a verifiable source for the JAG ruling that match grade HP can be used against lawful and unlawful combatants?

posted 12-31-2003 10:02               

You are correct; it appears my recollection was not accurate. I was not able to access the link in your post, but I did find an article by Fackler entitled "Military Rifle Bullet Wound Patterns" ( http://www.ammolab.com/military_bullet_wound_patterns.htm ), in which Fackler describes the wound pattern of the 5.45x39mm as follows:

quote:

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Soviet 5.45x39mm - This is fired from the AK-74, which is the Soviet contribution to the new generation of smaller-caliber assault rifles and which produces the wound profile seen in Fig. 3. The full metal-jacketed bullet designed for this weapon has a copper-plated steel jacket and a largely steel core, as does the bullet of its predecessor, the AK-47. A unique design feature of the AK-74, however, is an air-space (about 5mm long) inside the jacket at the bullet's tip (Fig 1). The speculation that this air-space would cause bullet deformation and fragmentation on impact proved to be unfounded, but the air-space does serve to shift the bullet's centre of mass toward the rear, possibly contributing to its very early yaw. In addition, on bullet impact with tissue, the lead just behind the air-space shifts forward into this space. This shift of lead occurs asymmetrically and may be one reason for the peculiar curvature of this bullet's path in the last half of its path through tissue (Fig 3). Only in a shot with a long tissue path, like an oblique shot through the torso, would this curved path be evident; it doesn't really add anything to wounding capacity, but might cause an occasional confusing path through tissue. This bullet yaws after only about 7cm of tissue penetration, assuring an increased temporary cavity stretch disruption in a higher percentage of extremity hits; other bullets need more tissue depth to yaw and in many cases cause only minimal disruption on extremity hits.

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A reminder to think twice and check sources before posting. My apologies.

However, I stand by my argument that since we are already using fragmenting bullets (i.e., M193 and M855; see Facler article cited above), the nose configuration of the OTM Match bullets used in the 6.8x43mm SPC should not be cause for concern.

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Alfadog
NRA Life Member

Christians believe God sent his only son to die for them.
Muslims believe they must send their sons to die for Allah.
Draw your own conclusions.

posted 12-31-2003 10:39               

quote:

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Originally posted by Chuck:
[B]Maybe I missed it in this thread, but can someone provide a verifiable source for the JAG ruling that match grade HP can be used against lawful and unlawful combatants?

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I have a citation from a ruling on it onmy home computer - when I get back off leave I will post it.

-Kevin

posted 12-31-2003 10:42            

quote:

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Originally posted by DocGKR:
Different bullet diameters from 6 mm to 7.62 mm were tested, using multiple bullet types, shapes, and weights from 90 to 140 gr...

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The photo of the SPC lineup is quite interesting to see, Doc. Can you please follow up with muzzle velocities and bullet weights for each caliber shown?

posted 12-31-2003 11:00            

quote:

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Originally posted by DocGKR:
[B]The Russians already produce 7.62 x 54 mm sniper ammunition that fragments similar to U.S. M852 and M118LR.[B]

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Fascinating photo of the 6.8 SPC gel tests. Thanks for posting it.

Yes, I know of the Russki sniper round, which has a dual core like that of 5.56mm M855 Ball, with steel tip and lead base. However, in my post I wrote that "most" ball rounds (other than 5.56mm) in use worldwide do not fragment. There are exceptions, such as some German 7.62x51, and the 7.62x54R sniper round, but they are the exception, not the rule.

posted 12-31-2003 14:58               

Thanks; enjoy your leave. Now is that Canadian JAG or US ?

And at the risk of irritating everyone with semantics, the Staff Judge Advocate (SJA) "opines" and Judges issue "rulings" !

posted 12-31-2003 15:45               

Again, I know this thread is about the 6.8 SPC, but let me make one correction about the 6.5 Grendel. While the 7.62 x 39 case is tapered, the PPCs as created by Palmisano are two generations removed from the parent case and are basically as straight-walled as any other modern case like the .223 and .308. Thus, the Grendel uses M16 magazines with the standard external dimensions and form-factor of current issue, just like the 6.8, and not curved ones like the AK series.

posted 01-01-2004 06:09            

Will reloaders be able to match the factory ballistics? Thank you.

posted 01-02-2004 01:18            

Chuck: Several legal reviews on the use of Open Tip Match, Frangible, and R2LP ammunition have indeed been written by the JAG office covering the use of such ammunition in different circumstances by various U.S. forces. In general, the military use of OTM projectiles in 5.56 mm, 6.8 mm, 7.62 mm/.308, and .300 Win Mag has been declared to be consistent with the international law obligations of the United States, including the law of war. If you are Army CID as you wrote, then I can assist you offline in acquiring information from the appropriate sources.

John Hanka: If the .26/6.5mm Grendel can reliably feed 25+ rounds through standard contour M4/M16 mags, that is great! I have not as yet seen one of the 25 round mags for the Grendel, however, David Fortier mentioned in his Shotgun News article that the folks at Alexander Arms used “modified steel USA brand 7.62x39mm magazines” in developing the Grendel. Likewise, some of the early SPC variants required magazines with greater curvature to have 25+ rounds feed adequately.

Bigfoot: Before Remingon began factory producing the ammunition, all of the test ammunition was handloaded—it will be no big deal for handloaders to safely match or even improve on factory ballistics.

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posted 01-02-2004 02:55            

6.8mm Rem SPC (RM68R1) 115 MatchKing® BTHP

quote:

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Premier® Match. Ever hear the phrase, “you could drive tacks with ’em?” Well they’re probably talking about Remington® Premier® Match ammunition. Using only match-grade bullets, Premier Match ammunition employs special loading practices to ensure world-class performance and accuracy with every shot.

Developed in conjunction with the U.S. Military, the 6.8mm Remington SPC provides greater downrange effectiveness and ballistics than the 5.56x45mm. It’s unique design is based on the 30 Remington case, which has been necked down to 6.8mm(.277).

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posted 01-02-2004 07:47            

It's also a little disappointing to see 2800fps from a 24" barrel. I expected something just this side of 3000.

[This message has been edited by Bigfoot (edited 01-02-2004).]

posted 01-02-2004 12:00               

quote:

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Originally posted by DonD:
Perhaps I am wrong but I suspect that the comment on Remington's web site regarding 24" barrels may be just someone adding their standard catalog caveats. I think MSTN is saying about 2650 out of a 16.5" barrel which would certainly suggest 2800 or better out of a 20" barrel. Hope I'm not wrong. Don

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Law of Diminishing returns...

posted 01-02-2004 12:36            

quote:

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Originally posted by DocGKR:
STAN2: Numerous bullet weights and configurations at various velocities were tested for each of the experimental SPC calibers that were depicted...I am afraid it would not be possible to take the time to list them all.

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I'm mainly interested in the 6mm SPC. Would greatly appreciate muzzle velocity for any bullet weight(s) of 90-100 grains.

posted 01-02-2004 16:52               

"If you are Army CID as you wrote, then I can assist you offline in acquiring information from the appropriate sources."

Thanks, I would appreciate the info. I can provide anything you need to verify my employment/status. You have no email address listed; what would you like and how should I provide it to you?

Thanks,

posted 01-02-2004 17:24            

Obviously the decision has been taken and so the question is just one of curiosity, not challenging the result.

I have shot 6.5 mm in the long match barrels you refer to for some years mostly because they seem to be a "sweet spot" in recoil/exterior ballistics/and, most importantly, the choice of match grade bullets. The choice of match grade 6.8 mm bullets has been rather limited, but I would not expect the exterior ballistics to be terribly different between the two bores "given similar bullets".

What sort of 6.5 mm bullets were tested in the SPC case? Did the decision to adopt the 6.8 x 43 SPC come down to a choice of "the best available bullet" in terms of its terminal/wound ballistics rather than any particular difference in exterior ballistics?

I do seem to recall seeing something (I do not remember where) that the 115 gr 6.8 mm bullet was selected over a somewhat heavier one because of a desire to flatten the trajectory out to 300 meters (presumably for rapidly engaging targets without having to make large sight picture changes).

Thanks

posted 01-02-2004 18:36            

quote:

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Originally posted by Ronin1:
The choice of match grade 6.8 mm bullets has been rather limited, but I would not expect the exterior ballistics to be terribly different between the two bores "given similar bullets".

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Of course you're right, if the 6.5 PPC were loaded with a bullet of similar configuration to that of the 6.8 SPC, there wouldn't be much difference in exterior ballistics between the two. However, why would anyone want to do that?

The major drawback to the SPC is that the 43mm case is not compatible for use with highly streamlined bullets of the type used in the 6.5 PPC. The 6.8mm projectiles are, of necessity, rather stubby. The 115-gr 6.8mm MatchKing has a ballistic coefficient of 0.344, which is greatly inferior to the 0.530 BC of a 123-gr 6.5mm Lapua match bullet.

The advantage of the shorter PPC case is that it can be loaded with either very streamlined, long-range bullets, or the shorter, SPC-type projectiles. In contrast, the SPC case is too long to load bullets of high ballistic efficiency.

If you did wish to load the ballistically-inefficient SPC-type bullet in the PPC case, you might as well "stretch" the PPC case to 43mm length. This would increase powder capacity and, naturally, muzzle velocity to significantly more than that of the SPC.

posted 01-02-2004 18:53            

quote:

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Originally posted by STAN2:
Of course you're right, if the 6.5 PPC were loaded with a bullet of similar configuration to that of the 6.8 SPC, there wouldn't be much difference in exterior ballistics between the two. However, why would anyone want to do that?

The major drawback to the SPC is that the 43mm case is not compatible for use with highly streamlined bullets of the type used in the 6.5 PPC. The 6.8mm projectiles are, of necessity, rather stubby. The 115-gr 6.8mm MatchKing has a ballistic coefficient of 0.344, which is greatly inferior to the 0.530 BC of a 123-gr 6.5mm Lapua match bullet.

The advantage of the shorter PPC case is that it can be loaded with either very streamlined, long-range bullets, or the shorter, SPC-type projectiles. In contrast, the SPC case is too long to load bullets of high ballistic efficiency.
Stan

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Stan,

Actually, what I though that I had understood was that there had been both a 6.5 mm and a 6.8 mm SPC tested. I may have been misunderstood in this, however. If, for example, one was to load a 108 gr or 123 gr Lapua Scenar in an SPC case (or something else as I gather that the 115 gr 6.8 mm bullets were "made to order") I was wondering what the difference might have been in terms of what was desired? (Presumably terminal ballistics.) The 108 gr 6.5 mm Lapua, for example, does quite well out through 400 yards in terms of drop and wind drift when fired at around 2800 fps out of match barrels which are mild loads. At 400 meters the heavier 139 gr Lapua has about a minute less wind drift, but both of them have a lot less than a 308 with 168 gr MKs and are much easier on the operator (recoil wise) over a course of fire when using a ten pound (or lighter) rifle.

Regards,

Rick

posted 01-03-2004 00:37               

I think that is what alot of us are looking/hoping for. But what I keep seeing are photos of 6.8x43mm guns built around Stainless HBAR Brls with muzzle brakes. Not exactly "compact."

posted 01-03-2004 02:31            

The PPC is definitely a superb match and long range cartridge; however, they are not as reliable as the SPC—remember, you don’t get any “alibi’s” in combat. Try leaving 25+ round magazines loaded for a week while on patrol in a dusty environment and see which functions more reliably--PPC or SPC…or you might try shooting them full-auto or even belt feeding them and see which has less stoppages… FWIW, the Remington factory 6.8 mm SPC 115 gr loadings appear to be very conservative with pressures and velocities—they are running approximately 100 f/s slower than the AMU handloads we extensively (and safely) tested earlier.

Ronin1: The majority of the 6.5 mm SPC loads used OTM and polymer tip bullets of 100 gr, 120 gr, and 140 gr. In testing, the most important consideration was reliability in feeding and function, followed by accuracy, then barrier penetration and terminal performance. Remember, the final version had to meet all the previous listed requirements, including passing a JAG legal review.

posted 01-03-2004 04:09               

quote:

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Originally posted by CANADIAN_TACTICAL:
I have a citation from a ruling on it on my home computer

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This one Kevin?