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Old June 26, 2009, 10:49 PM   #1
Topthis
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6.8spc vs. 6.5 Grendel

So, as I understand it, I can get either of these Uppers and place it on top of my AR15 lower without having to do anything but perhaps get different magazines. Now with that said...I am trying to figure out which one of these I should go with? I am clueless as to the pros and cons of either of these, so I thought I would put it to my fellow TFL'er to chime in. Does anyone have any advice? The Upper will serve mainly as adding variety to my shooting and perhaps doing some hunting in the near future. Thanks all!
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Old June 26, 2009, 11:24 PM   #2
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There both really good cartridges. I think the 6.5 grendel has more recoil. But then again you have a 1000 yard capable system with it. 6.8 seems to be more popular. I'm all in favor of 6.5 would be a hell of a varmint round.

http://www.youtube.com/watch?v=Cgrkp8N0HUs

http://www.youtube.com/watch?v=OwtMo5-NU1A

Sounds amazing lol

Second one is future weapons. Never seen this one before but it's on the 6.5 grendel.
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Old June 26, 2009, 11:37 PM   #3
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6.5 Grendel

See PM sent...
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Old June 27, 2009, 12:25 AM   #4
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If you want it for hunting i would recommend the 6.5. It has better performance at longer ranges and while both are excellent cartridges I think the 6.5 is better suited for hunting applications.
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Old June 27, 2009, 12:56 AM   #5
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Grendel for a hunting rifle.

SPC for a fighting rifle.
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Old June 27, 2009, 02:32 AM   #6
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You don't really see as much in the way of Grendel as you do 6.8 SPC. The Grendel was designed as a target cartridge while the 6.8 was designed as a fight stopper. The selection of ammo for the 6.8 is better if you can find any, and because it shares a bullet with the 270 (.277") there are lots of choices for the reloader. Speaking of which Chuck Hawks has a comparison on his members only side and rates them about the same as a hunting cartridge out to 275yds, but again the bullet selection is better for the SPC. You just have to decide how what you intend to use it for. Shown below is my AR15Performance 6.8 Xtreme upper. These come with a SPCII chamber and a 1 in 11.25 twist barrel. Those are critical improvements over the older Remington SAAMI spec chamber and 1 in 10 twist.

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Old June 27, 2009, 02:34 AM   #7
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I know this has little to do with the OP, but I wish I could neck the 6.8 down to 6.5 and 6mm and various shoulder angles.
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Old June 27, 2009, 03:00 AM   #8
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Quote:
10-96 said: I know this has little to do with the OP, but I wish I could neck the 6.8 down to 6.5 and 6mm and various shoulder angles.
I don't want to derail the thread either, but looking at the case dimesions I think a very workable pseudo-Grendel could be made from the 7.62x39 case necked to 6.5mm. I've even thought about trying this with one of the little CZ-527 carbines.

With an AR, though, I'd think that 6.8 SPC factory rounds are much easier to find than 6.5 Grendel ones.

Last edited by JackL; June 27, 2009 at 03:02 AM. Reason: Afterthought.
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Old June 27, 2009, 09:47 AM   #9
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Think of the type rifle/barrel length you want, too. If you want a short barrel (18" or less) or especially a SBR, go 6.8. If you want the long, target/prairie dog type barrel (19+"), then the 6.5 works and has a higher BC, FWIW. The Grendel needs a longer barrel for its published specs. The 6.8 is pretty much maxed out by 18".
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Old June 27, 2009, 05:39 PM   #10
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Thing is the 6.5 would take down a man just as well. You have great penetration also. Then there is the beyond 600m part. I still say 6.5. The only thing i would give to the 6.8 is case design, grendel looks like it could have feeding problems.
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Old June 27, 2009, 07:08 PM   #11
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I know this has little to do with the OP, but I wish I could neck the 6.8 down to 6.5 and 6mm and various shoulder angles.
Already been done by Robert Whitley and John Holliger, among others.

The 6.8 can be a good long range cartridge too. It has a little more capacity than the Grendel. It would just have to be loaded long and single fed.

Unfortunately, high BC (read match) bullets aren't as available for the 6.8mm bore diameter as they are for the 6.5mm. There's just nothing like a Lapua 139 available in 6.8mm.
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Old June 27, 2009, 07:15 PM   #12
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If could build one right now it would by 6.5.
After everything I've read its a better all around round.
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Old June 27, 2009, 08:55 PM   #13
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Based on published specs and my personal preferences, I've always wanted to get a Grendel. I like shooting things far away. I like precision. But you know, things have changed. The original 6.8 SPC chamber and pressures and rifling twist, etc, etc, was all messed up by Remington. Now the world has moved on. A new chamber (SPC II + others) and slower twists with fewer grooves has resulted in some amazing specs. I can't see how the Grendel has much left to brag about. And it is STILL hard to actually buy Grendel uppers and Grendel ammo. This proprietary stuff gets old after a while.

So I recently had a smith build me a 6.8 White Oak upper for my AR. I still don't have it in hand but I'm looking forward to it. I've bought some factory ammo plus brass and bullets so I'm very much looking forward to loading for it. And I've been reading a lot.

http://68forums.com/forums/showthread.php?t=310

I'm especially interested in some of the results people have been getting with the Barne's TSX bullets. A 16" barrel sending one of those all copper bullets downrange at WELL over 3000 fps should kill deer out to extended ranges. (Some are getting them up to 3200 fps out of a 16" barrel.)

http://www.ar15performance.com/

Place to buy proper factory loads and the right kind of brass. Small primer pockets!

http://www.ssarmory.com/

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Old June 27, 2009, 08:55 PM   #14
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Quote:
Unfortunately, high BC (read match) bullets aren't as available for the 6.8mm bore diameter as they are for the 6.5mm. There's just nothing like a Lapua 139 available in 6.8mm.
According to Chuck Hawks analysis the high BC bullet is the only advantage that the 6.5 possessed over the 6.8. "If both cartridges were loaded with bullets of similar form, most of the 6.5's advantage would melt away." When you add in the fact that Remington blew it with it's chamber specifications and 1/10 twist, and the newer hotter loads fired from a SPCII chamber and 1/11 twist barrels and I think the pendulum swings toward the SPC. Still if I were looking for a long range target round I'd consider the Grendel, and go with the SPC for anything else.
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Last edited by sholling; June 27, 2009 at 09:04 PM.
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Old June 27, 2009, 09:06 PM   #15
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Not really much of a comparison. After all, isn't the very idea of the BC for bullets used for each load the basis of ballistic comparison between all calibers? Chuck Hawks is also widely known as a Chuck O'Conner, widely touting performance of the .270 calibers over even the higher BC and SD bullets in the 7mm and .30 cals. despite all charts and performance reports proving otherwise. He still has a verifiable plethora of good info available, though.

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Old June 28, 2009, 12:59 AM   #16
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Two advantages for the 6.8: Bolts and mags

The 6.8 can run at higher pressures because of the stronger bolts. Harrison at http://www.ar15performance.com/ makes a super strong 6.5 bolt that negates this advantage however.

The C-Products 6.5G mags still aren't reliable yet because of QC issues and they are limited to 2.8" OAL. About half of the C-Products mags are reliable.

The PRI 6.8 mags are very reliable and can be loaded to around 3.1" OAL.

The 6.5 has great bullets that equal the 6.8 for defence. http://www.65grendel.com/forum/showt...ghlight=berger

For hunting not much difference between them.

If you pick a strong 6.5 bolt and happen to get good mags for it then the only real world difference is the expense which favors the 6.8 at the present. If (a big IF) by using the strong 6.5 bolt and a minimum twist barrel allowing similar velocities to the improved 6.8 (ask Harrison in the link about this) the 6.5 might (repeat MIGHT) make the better cartridge.

And here's a tip on making the 6.5 cheaper, there are other barrels and reamers that are identical to the Grendel's specs, 6.5 AR for one IIRC. The Grendel is just a 6.5 PPC with the shoulder slightly forward, nothing special really.
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Last edited by Big-Foot; June 28, 2009 at 02:12 AM. Reason: Forgot to mention the 6.5 G clones.
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Old June 28, 2009, 02:20 AM   #17
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"...and because it shares a bullet with the 270 (.277") there are lots of choices for the reloader."


You must be kidding or you know nothing about 6.5mm bullets!!!

The selection of bullets for the 6.5mm is FAR BETTER than for the .277". This is especially true of super high quality, high BC match bullets (only .224" and maybe .308" bores have a better selection.

When you understand that only the lighter weight .270 bullets are usable in the 6.8mm SPC you will realize that the bullet selection for the 6.8 is actually rather limited.

In contrast to this, although optimized for (around) 95g to 130g bullets the Grendel will handle nearly the full range of 6.5mm bullets. The Grendel works well with 75g to 144g (or 155g). Only the very heavy 160g RN bullets are unsuitable in the Grendel.


For those that want to compare muzzle velocities between these cartridges...

Yes, it is heracy to the armchair experts but, muzzle velocity does NOT MATTER AT ALL!!!

What DOES MATTER IS RETAINED VELOCITY, or how much velocity/energy the bullet still has when it hits the target.

This is why BC is so important.

Given the same bullet design/shape, at any selected weight the 6.5mm is going to have a higher BC and higher retained velocity.

The same is true of SD. Given the same bullet design/shape, at any selected weight the 6.5mm is going to have a higher SD and greater penetration.


The 6.8 SPC may be a good "short range" cartridge but the Grendel is AT LEAST EQUAL. At "medium ranges" the Grendel is FAR SUPERIOR to the 6.8 SPC. At true "long ranges" the 6.8 SPC is SO FAR OUTCLASSED it is a joke in comparison to the Grendel!!!


The supposed advantage of the 6.8 SPC in short barreled rifles is not due to any advantage in the cartridge itself. The advantage is due to the powders used. Since most Grendels are 16" or longer and shot at longer ranges the "powders of choice" are those that give better performance for these factors. A change in powder choice would improve the Grendels short barreled rifle performance again at least matching if not exceeding the 6.8 SPC at every range.

C.
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Old June 28, 2009, 02:58 AM   #18
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For the ones who want to neck down the 6.5 Google the 6mmAR and the 6mmAR Turbo, you can make the cartridge from a 6.5 Grendel, 220 Russian, 6 PPC or 7.62x39. When you wildcat you can just about do anything you want.

Me I would go with the 6.5 Grendel, bullets are much better and you have more choices, but if you didn't want to change your barrel go with the 6mmAR Turbo and keep the 1:7 twist and shoot the heavier bullets and faster than the regular 223. All your into it for then is dies and brass.
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Old June 28, 2009, 08:33 AM   #19
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My experiences with the 6.5 Grendel was not that good. There is potential in the cartridge but it was a PITA.

I really liked what the cartridge claimed to be. I've always been a 6.5 mm bullet fan...they "hit harder than they should" due to the excellent BC and trajectory and the SD numbers for penetration. I was looking to get a 800-1000 yard gun in an AR15 package.

I bought a 24" AA Overwatch upper. Difficult as heck to find components to reload (even before Obama-mania). Long waits from AA. Bought Wolf Gold to get cases...they wouldn't feed and turned the rifle into a single shot/hand feed. The cases bulged in the AA barrel and were unloadable.

The cartridge was finicky with over 20 loads tried. I finally gave up...the reality didn't live up to the hype for me. Too much trouble trying to get and "accurate" cartridge to be accurate. I've been reloading for 25 years and have crafted extraordinarily accurate rounds for many cartridges...but couldn't make it happen with this rifle.

I built an 18" 6.5 Grendel upper to see if it was just the Overwatch upper I was having trouble with. I had EXACTLY the same issues with this one.

I finally got sick of dinking around with the cartridge and sold both uppers and built a 6.8 SPC upper. It is not an accuracy machine but holds its own (~1.5 MOA) with perfectly adequate accuracy. It has much more punch than the 5.56 and with the comp I have on it the recoil is much less than a .308 in a package that is less weight as well. I am very pleased with it.

Hopefully my experiences were unique and/or things have gotten better. However, if I want a 1000 yard semi auto in the future, I'll get a AR10 sized lower and get a .260 or a 6.5 Creedmore.
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Old June 28, 2009, 11:27 AM   #20
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Quote:
The 6.8 SPC may be a good "short range" cartridge but the Grendel is AT LEAST EQUAL. At "medium ranges" the Grendel is FAR SUPERIOR to the 6.8 SPC. At true "long ranges" the 6.8 SPC is SO FAR OUTCLASSED it is a joke in comparison to the Grendel!!!
I think we need some numbers here rather than just words. What is "medium range?" I own my own 90 acres and I hunt here. There are lots and lots of trees. Most of my deer are killed at 75 yards or less. If you get really lucky and get an opening through the trees into another meadow, you _might_ be able to squeeze in a 200 yard shot. Let's be generous and extend that to 300 yards. My contention would be that the average deer hunter or coyote eradicator is going to consider 200-250 as medium range and 300-350, maybe 400 as "long range." I've personally never pulled the trigger on a live animal that was over 300 yards.

My point is that I don't think those super high BC bullets are going to really come into play for the vast majority of people who want to use these as sporting rifles. If we zero the 85 grain TSX bullet at 200 or 250 yards, what will drop look like at 350 or even 400? (3100 fps.) People are trying to talk Barnes into making a slightly heavier and longer version with the polymer tip. That might be the ultimate hunting bullet for the cartridge.

I'll grant you that you could take a short barreled 6.5 Grendel and load it with faster powders to make it perform better. But then you would also you use the shorter and lighter bullets that you don't respect in the 6.8. How much velocity could a Grendel really achieve with a 139 grain bullet and a 16" barrel? At the lower pressures which are standard for the cartridge?

I personally see the Grendel as a more specialized cartridge. If I was buying one, I would go with a long barrel.

I think these discussions get a bit off track because people start arguing different environments. The OP said he was looking for a hunting and fun range cartridge. IMO, the 6.8 is better for that than the Grendel. (Especially if you really play fair and consider availability of components and parts.) Now whether the Grendel or the 6.8 SPC II would be better for use by the military is a totally different subject. If it is going to be used in light machine guns, true long range becomes important. By that I mean 600-800 meters. It is quite possible the Grendel is better there. But you also have to consider which design feeds better from a belt. That seems to favor the 6.8 again. Back and forth, back and forth. I think most of us would agree the result would be a better round for our troops though.

But in _this_ thread, the debate started with the OP and hunting. IMO, that really does favor the 6.8. Shorter rifles that produce full velocities. Bullet choices that work well on deer, coyotes, and pigs. Brass that I could order today and get this week. Uppers that I could order this today and get this week.

I don't think one cartridge has to preclude the other. I own the one 6.8 but I could still see buying a 24" DMR style rifle in 6.5 Grendel. But I suspect I know which one would end up with the higher round count over time. If for no other reason than component prices and availability.

This thread on "the state of the 6.8" just keeps growing:

http://68forums.com/forums/showthread.php?t=6692

Gregg
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Old June 28, 2009, 02:43 PM   #21
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I have been wondering about the 6.5,myself.I'm not really interested in the 6.8.
It is an issue for me that the only PPC brass (6mm) is anout $1 apiece.
So,does it work out well to get 7.62 x 39 WW brass,and do sort of an Ackley improved fireform process?.I mean,neck the 7.62 brass to 6.5,creating a small headspacing shoulder?.Load them for fireform into a 7.62x39 mag,shoot them,and the shoulder and case taper should get blown out.

JD Jones at SSK also works with this stuff.

I am hungry to learn all I can,so I'll keep reading
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Old July 8, 2009, 01:50 PM   #22
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Thanks all for the information...it looks like I may have to go with the 6.8spc just because of the availability of them versus finding anything in 6.5 Grendel. If the 6.5's become widely available down the road, I may take a look at them. Thanks again.
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Old July 8, 2009, 02:57 PM   #23
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6.8
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Old July 23, 2009, 02:07 PM   #24
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iamkris, HAPPY B-DAY!!!
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Old July 23, 2009, 02:12 PM   #25
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I also vote 6.8 because of availability issues but I think the Grendel is a superior cartridge.

Quote:
I personally see the Grendel as a more specialized cartridge. If I was buying one, I would go with a long barrel.
Why so? I was under the impression that the Grendel was developed as an intermediate cartridge to solve the problem of the weakness of 5.56 NATO from a carbine length rifle, except without the endorsement of SOCOM that the 6.8 enjoyed. I see it as being more specialized as an all-around combat cartridge designed to perform well as a manstopper in both carbine length and full length rifles. I could be wrong though.
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