6.5 MPC--Viable Alternative?

[Samarkand]

I don't have much of a dog in the 6.8 SPC vs. 6.5 Grendel fight. From what I've seen, they're both interesting alternatives to the current 5.56 Nato. But they both have a problem in that they require current weapons to be redesigned to be used as a service cartridge. 6.8 needs new magazine and (I believe) bolts, while 6.5 Grendel has an odd shortened case that wouldn't fit SAW belts and would need changes to the SAW's feed system.

Then I read about SSK Industry's 6.5mm Multi Purpose Cartridge--a re-necked 5.56 case taking a 6.5mm bullet. *squint* It looks promising--closer to the Grendel's better ballistics, decent increase in potential hitting power with a wider diameter bullet (30-50%, according to the designer), and most importantly compatible with existing 5.56 magazines/bolts/ammunition belts. Just put on 6.5 MPC barrel, and you're done. As for wounding potential...well, I believe that within a certain "class" of caliber, variation in wounding effect is more due to bullet construction than the diameter.

Anyone with more-than-casual knowledge of ballistics can tell me if the 6.5 MPC might be the "new service cartridge" that the military might accept? It may be what SOCOM might use as a compromise against the 6.8 SPC. If a barrel change is the only switch needed in field, SOCOM could use 6.5 MPC'd weapons for their own use while being able to quick change back to 5.56 if ammunition compatibility is needed for operations with regular troops.

Samarkand

 

[otomik]

The SAW isn't looked upon as perfection, they'd really like to go to something like Singapore's Ultimax LMG. Ergo, existing belts aren't priority, polymer cases would have a few interesting advantages so if we wanted polymer cased ammo the existing metal belts probably wouldn't work too well. Now that I think of it I also want transparent polymer magazines as well.

If I wanted the most convienent way to increase lethality I could just go back to a 20 inch barrel and use a heavier bullet (the 1 in 7 inch twist should be able to handle something heavier than SS109), as well as a specialized DMR cartridge with a boat tail and made to closer standards.

 

[OldSchooler]

I always find it interesting to note the talk of "increased hitting power," or whatever you want to call it. These new cartridges and their consideration are supposed to fix a shortcoming in the much vaunted 5.56 round, which seems to work pretty good, according to most proponents.

Personally, I find it refreshing that the old arguments of stopping power are seen as valid. After all these years we are moving back to the middle, it seems, with the consideration of near 7x57 ballistics.

I always thought that tactics were supposed to supplant the need for shock power. I guess what's new is old...

 

[rangerruck]

read that same info on the 6.5 cartirdge, very good ballistics. the problem here is two fold. remmy allready has alot invested in the 6.8 and has their lobbyists, and their friends on the hill, hitting the schmooze patrol hard over the last two years. Also even thought space to carry the rounds, carts, beta-c's , belts are the same, you esentually double the weight that a grunt carries in ammo.
tough pill to swallow for congress, and their homies in the pentagon, also State dept. will want to have a "unofficial" say, as they are all friends with our enemy countries, who will whine to state how it is not fair we have better rounds now.

 

[HorseSoldier]

I've never quite understood the appeal of the Grendel for a service round. It has great ballistics out to 1000 meters -- great, and fired through a 3-4 MOA service rifle or carbine, mostly with iron or red dot reflex sights, that means at 600 meters (if you can see the target at all) you're hitting within a couple feet of the target, however good your ammo is . . .

Being able to reach out that far is nice and all in some circumstances, but if it means any loss of, say, feeding reliability due to that stubby little Grendel case, then I'd say it's a giant leap in the wrong direction.

 

[rbernie]

fired through a 3-4 MOA service rifle or carbine, mostly with iron or red dot reflex sights, that means at 600 meters (if you can see the target at all) you're hitting within a couple feet of the target, however good your ammo is . . .

As I understand things, the 6.5 Grendel is not supposed to be a replacement chambering for all M16-platform rifles but as a potential candidate for a DMR chambering using specially accurized rifles.

Back to the original question - I'm not convinced that upping the caliber is worth the effort until the new chambering also offers an increase in powder capacity. I think that the rationale for the 6.5 Grendel and 6.8 SPC chamberings is that both increase the caliber and also increase the powder capacity (however modestly).

 

[HorseSoldier]

As I understand things, the 6.5 Grendel is not supposed to be a replacement chambering for all M16-platform rifles but as a potential candidate for a DMR chambering using specially accurized rifles.

It could be viable in that role, but seems like a lot of the internet buzz is from the "5.56mm is less lethal than a Red Ryder BB gun" crowd.

In the DMR role, though, it's just another link in the logistics chain, when you can do about as well with an SPR and Mk 262 ammo, or better with a .308 long gun.

 

[Crosshair]

The problem (That I have with it at least) with 5.56 isn't that it lacks lethality against tissue. (With proper bullet construction) The problem is when it has to go through stuff to get to the small tissue. A few friends and I where shooting at old chunks of sidewalk concrete that we got from a construction site. Surplus 5.56 was unimpressive, just small chunks getting blown off. 22-250 loaded with 55 grain FMJ-BT wasn't much better. 7.62x39 it gets interesting, bigger craters and the chunks are breaking up. .308 really breaks them down quick. One person had a Model 88 in .243 and it defeated the brick monster very well. A little better than the 7.62x39.

I'm not saying that we should go back to .308 for everyone. I'm just saying we need something that is a little better in the brick busting/barrier penetration department. People tend to hide behind stuff and you need to bust through it. There seems to be some problems with that using 5.56.

/Just adding my oppinions to the debate.

 

[HorseSoldier]

I'm not saying that we should go back to .308 for everyone. I'm just saying we need something that is a little better in the brick busting/barrier penetration department. People tend to hide behind stuff and you need to bust through it. There seems to be some problems with that using 5.56.

There's always the AT-4 and HEDP rounds from the M203s.

 

[Crosshair]

There's always the AT-4 and HEDP rounds from the M203s.

Lot of people I know in the military do not think highly of either of those weapons for different reasons.

 

[otomik]

.308 really breaks them down quick. One person had a Model 88 in .243 and it defeated the brick monster very well. A little better than the 7.62x39.

I'm not saying that we should go back to .308 for everyone. I'm just saying we need something that is a little better in the brick busting/barrier penetration department. People tend to hide behind stuff and you need to bust through it. There seems to be some problems with that using 5.56.

.223 Remington has a maximum pressure of 55,000 psi
5.56mm NATO has a maximum pressure of 60,000 psi

I don't think 65k 75k psi is an unreasonable design goal especially if we had a rifle that wasn't as susceptible to receiver wear. Also a longer heavier bullet moving faster (no faster than 3,500 fps to avoid barrel wear issues) would result in a shorter time of flight and flater trajectory. All this talk about a lack of lethality and poor ballistics is at a time when the military has gone to short 14 inch barrels when they could easily have 20 or so in a bullpup layout. In short I don't think we need a totally new cartridge, just a thoughtful redesign from 5.56mm NATO to .223 AMERICAN.

 

[rangerruck]

lemme break in here, this is not the grendel, this is a 556 case completely, blown out , straight to shoulder with sharper angle and shorter neck. it is completely compatible with all weapons that use the 556. the ohly change would be the bbl, not even the mags change, nor the links for the saw.

 

[max popenker]

Ok, and why not to go in a different direction? I mean, to retain 5.56 bulet and make a smaller and lighter case, like that?

This is from 2005 NDIA Small Arms conference stuff, so it could be done easily, i suppose.
And that way you'll get what, 50-round magazine in the same size & weight as your 30-rounder. More ammo - more hit probability, huh?

 

[Delmar]

[B]I'm just saying we need something that is a little better in the brick busting/barrier penetration department[/B]

I think Ma Deuce has that issue well covered.
NOBODY likes to argue with Ma!

 

[db_tanker]

Isn't the 6.5 MPC simply the 6.5 TCU?

I don't get people somtimes...Wes Ugalde had the 6mm, 6.5, 25 and 7mm TCU's all made before the 6.5 Grendels and 6.8 SPC's were gleams in their respective creators eyes...

Have had the pleasure of shooting both the 6 and 6.5 TCU's, both in 12" barrels and both were VERY accurate out to 150 yards...this being in a pistol config with a 4x scope...

BTW, for those who don't know the TCU's were made for pistol sillhouette shooting...the larger bullets were better able to buck the wind and were also better able to knock down steel "rams"...in my reading they found that the 223 case was best when used with the 6.5, but at that time the availability of quality bullets kinda killed the cartridge...the 6mm, however, did VERY well with the popularity of the 243 Winchester and its wide variety of bullets available to it.

D

 

[otomik]

This is from 2005 NDIA Small Arms conference stuff, so it could be done easily, i suppose.
And that way you'll get what, 50-round magazine in the same size & weight as your 30-rounder. More ammo - more hit probability, huh?

less recoil as well if the powder is used more efficiently in a smaller case. very interesting, I was hoping you'd show up. it brings up the question what kind of case pressures are practical in a service rifle? the Soviet and Chinese intermediate cartridges are all lower pressure than american 7.62mm NATO and .223 NATO. is this because of metalurgy or preference for steel cased ammo?

 

[max popenker]

the Soviet and Chinese intermediate cartridges are all lower pressure than american 7.62mm NATO and .223 NATO. is this because of metalurgy or preference for steel cased ammo?

I think that lower pressures are better for botg gun & shooter - you have less barrel erosion and less muzzle blast.
Also, all these rounds were designed from ground sero for specific requirements, while 7.62NATO was built by "compressing" the .30-06 and .223 was built from hunting round which originally was NOT intended for a semi-auto rifle, even less a full-auto one.
Juts my $ .02 on that.

 

[6.5 MPC Advo]

Hello, All-
Some of you may be wondering where the information for this
thread was coming from FYI, the main article (so far) is posted
in the links to our web group, and anyone who has an interest in this topic
is welcome to join us there.
To add my perspective to the conversation-I think that a big company
associated with the color green has done a great disservice to the shooting
community. They hyped a new cartridge, and then it was almost impossible
(for a long time/until recently) to find either a weapon or cartridge in that
caliber. Now (nearly) everyone who likes the 6.8 is saying that it will be the
dominant player in the marketplace, due to it's "longevity" [what? 2 years,
on the outside, since it was supposedly 'introduced'] and the inc.'s great
"clout". I don't buy this. The launch was a botch job, and many of us non-.223 lovers got a bad taste in our mouths from the outset. The MPC has
definite advantages (and a few disadvantages) between it and the other 6.5/6.8 that will be evident as time goes on, and the word gets out about
it. Plus, millions (billions?) of $ could be saved by going to the MPC for the
U.S. taxpayer, if Uncle Sugar would use some good number crunching and
(sadly lacking) horse sense. They buy replacement barrels for 5.56 already,
so a switch to 6.5 would involve very little change, and would get cheaper
as production numbers were ramped up.
In the 'stopping power' arena, there has been case-upon-case documented
of .223 failing to stop quickly, dating back to Vietnam, and before. My buddies who have returned from combat have reported the same observations
in the current quagmire, and this was being complained about in Somalia, 13
years ago! It is time to stop mollycoddling Colt, Inc. and other .223
profiteers/advocates, and give we soldiers a better fighting rifle to kill Jihadists with!

Other Views/Communications Are Welcome-

 

[Stiletto Null]

^^^

I wouldn't be so annoyed with Remington if the 6.8 SPC didn't suck so much.

There, I said it.

On 6.5 MPC: what kind of muzzle velocities and bullet weights are we talking about? (For comparison to 6.5 Grendel)

Grendel's nice for inherent accuracy of cartridge, but if you can get the same V0 and bullets into a cartridge which is easier to feed and cheaper to manufacture, any gun (like, say, the AR platform) can be made to keep it under 3MOA. Isn't the military requirement 4MOA?

 

[KC&97TA]

The answers on all the experimental uppers and semi auto rifles I've seen, slide through the Marine Corps, lead back to one thing... The Infantry Squad and even further down to the Fire Team. Why change thier weapons systems? Why not just train them better with the 5.56mm? Train for failure drills, double taps, ect. Believe it or not, there's been times even in the Iraq campain, were ammo was taken from the dead, because they were that short of rounds. What needed to happen was more "team work" which sounds crazy, it's not really Team Work, it's integration of leadership and weapons management on the battle field.

I was a big fan of the 6.8, but it didn't happen. The DMR's started to fly out of Quantico and into Afgan and Iraq as fast as they can make them, putting added knock down power out there, but the primary weapons system has to be light, quick to recover from the recoil and INTERCHANGEABLE AMMO, if you do one, you have to do them all... The 6.8mm will fall by the wayside and more weapons like the SR-25 will come into battle. Many of us said this about the 6.8mm a few years back, so only time will tell, but the push for 7.62 assult rifles, that function just like the M16 is hearing alot of lip service right now.

...People tend to hide behind stuff and you need to bust through it. There seems to be some problems with that using 5.56

This is when you call "Engineers UP" or my personal favorite "SMAW"

 

[Stiletto Null]

^^^

Um. Our troops are damned well trained, and they're pretty good shots.

The complaints about about their bullets not doing the job once the troops put them there.

And speaking of improved ammo, there's already Mk 262...except that it's not general issue for anyone except for (some?) Marines.

 

[6.5 MPC Advo]

>6.5 MPC muzzle velocities and bullet weights?

All this information is on the website attached to my signature, and the link that is provided there. Y'all come!

 

[bowfin]

/*I think Ma Deuce has that issue well covered.*/

Nope.

I know a guy whose squad decided to ditch their M-60 and carry a M-2 .50 caliber on patrol in Cambodia, because they wanted something to go through bunker walls. Too many guys got hit trying to run their belt (or piece of one) of .50 caliber ammo over to the gunner.

I do have to admire their determination of those guys trying to get the upper hand in the battle! Carrying an M2! Holy Cats!

 

[cordex]

I know a guy whose squad decided to ditch their M-60 and carry a M-2 .50 caliber on patrol in Cambodia, because they wanted something to go through bunker walls. Too many guys got hit trying to run their belt (or piece of one) of .50 caliber ammo over to the gunner.

I do have to admire their determination of those guys trying to get the upper hand in the battle! Carrying an M2! Holy Cats!

They carried an 84lb machine gun on patrol? With or without the 44lb tripod? Plus ammo ... hmmm.

I think the point is that if you've got to blast through heavy cover, there are probably better tools than your rifle.

 

[Crosshair]

Mabee we should have not stopped issuing recoiless rifles. Alot lighter than an M2 and more versitile than a SMAW.