6.8 vs 6.5

aninchlow

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I know nothing about these two rounds but that they are now available to be chambered in my XCR. Out of the box this rifle rocks. and to go to a heavier bullet for a bit longer ranges is something that interests me.

Can someone please let me know the advantages / disadvantages of each.

thanks,

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6.8 SPC Specifications

Barrel Lengths
12", 14.5", 16"

Contour
Heavy (same as 5.56, but lighter due to larger bore)

Rate of Twist
1/10"

Grooves
4 Right Hand

Chamber
Latest 6.8 with .100" lead

Muzzle Thread
5/8x24

Lining
Chrome

Gas Adjustment
5 Setting Quick Adjust.

Magazine
6.8



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6.5 Barrel Specifications

Length
16", 18.6"

Contour
Heavy (same as 5.56 but lighter due to larger bore)

Rate of Twist
1/9"

Grooves
TBD

Chamber
6.5 RA

Muzzle Thread
5/8x24

Lining
Chrome

Gas Adjustment
5 Setting Quick Adjust.

Magazine
6.5 Magazine



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7.62x39mm Barrel Specs.

Length
12", 14.5", 16"

Contour
Heavy (same as 5.56 but lighter due to larger bore)

Rate of Twist
1/10"

Grooves
4 Right Hand

Chamber
Russian Spec.

Muzzle Thread
5/8x24

Lining
Chrome

Gas Adjustment
5 Setting Quick Adjust.

Magazine
M16 7.62x39mm*
 
I've never owned a rifle chambered for either round, but what I've heard is the following.

The 6.8SPC was developed to improve terminal ballistics from the AR series. In other words, to hit harder.

The 6.5 Grendel was developed for improve long range performance from the AR series.

I've heard the same information from a few sources, but I've never fired either round. I may be out to lunch here :D
 
From a kinetic energy perspective the 6.5 seems to carry more energy over a greater distance than the 6.8, from what I have read.

In my opinion, the 6.5 is the better round of the two, carrying more energy, over a greater distance, and apparently it works quite nicely out of shorter barrels as well.

But then again I couldn't find a whole lot of data comparing the two. So this is totally subjective.
 
I'm looking for a 14.5" AR in 6.5 Grendel. I know Alexander Arms and Sabre Defence Industries makes them. I assume I could import them through Questar if I want to pay the $300+ in fees. Or I could just import the upper, I guess. Anyway, before I look into that, does anyone know of anything currently available IN Canada that would fit my needs?

How about ammo? Is there anywhere in Canada I can get 6.5 Grendel factory ammo until I get setup for reloading?
 
Read an article comparing the 2. The one with the fatter case (can't remeber which is which) had disadvantages in regard to the current LMG, mag capcity and required new links for use in MG's. Also that it would not perform as well in the shorter barrel currently favoured by the troops.
 
AFAIK, someone correct me if I'm wrong, but 6.5 Grendel has superior ballistics/kills better and is more accurate at ANY barrel length.

But the angle of the neck does make it very hard for belt feeding. This is a moot point, as from the articles I've read, its evident that the US mil or anyone in NATO will never adopt this cartridge because they refuse to even acknowledge a problem with 5.56. Also, mag capacity is no longer an issue. I believe they now make large cap. mags in 6.5 Grendel.

Read an article comparing the 2. The one with the fatter case (can't remeber which is which) had disadvantages in regard to the current LMG, mag capcity and required new links for use in MG's. Also that it would not perform as well in the shorter barrel currently favoured by the troops.
 
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Like w_square said:

6.8 SPC was made to improve the terminal of the AR platform at longer range where the fragmentation effect is too reduced without trading the good CQB possibilities.

6.5 grendel is an improved 6.5 PPC (an offspring of 5.45x39 or .220 russian like all PPC rounds), It seems its ballistic is close to 7.62x51's. It compares to the SPC in power but retain energy much better at long range and it can use a lot more bullet types than the SPC without hampering its performances. The one problem that has been found is on the AR lug design, if you use a too hot reload it wears the bolt lugs much faster and it can be prone to failure unless you get the idea to make your own SDSM (super duper short magnum) out of your mind. But with the XCR... new possibilities maybe...

I've found a ballistic chart comparing 5.56, 6.8, 6.5 and 7.62 in different charges.

3w.65grendel.com/graphics/grendelballistics.pdf
 
Well that chart was super helpful. Thanks Toya.

A further question: When there are issues with belt feeding, are there issues with magazine feeding inside of a AR/XCR platform of the 6.5?

This is encouraging, I was shooting at a match a while ago, and my parter was hitting my target at 400m when a sudden wind squall picked up (he was shooting a 14" .223), it would have been a pain in the ass but the quirk of it was he was putting them in the 9 ring for me. :) I was shooting a m1a supermatch so my rounds were still on target, other then the fact that my trigger busted half way through it was good!

cheers,
 
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The 6.8 will not last, 6.5 grendel has a better design and is more versatile.



:) yes but that means nothing to the eggheads that make policy in the military. Its not what's best its whats adequate and cost less, oh and dont forget who makes it and how much they spend on selling their ideal to the right people. :rolleyes:
 
6.5 grendel was looked at when the 6.8 SPC was developed. 6.8 is a better combat round (which was the purpose of the 5th Group inspired initiative), and feed better reliably when the weapon is hot and dirty.
 
From what I have read, the 6.8 was selected due to it's harder punch when used for cqb or short range shots. The 6.5 has excellent ballistics out to and beyond 600m, but is also acceptable as a close range round.

I am personally going to go with the 6.5 for my next build, mainly because I don't have to clear "too many" (read "not at all") buildings with my personal rifle and I like the extra range for longer shots.
 
A further question: When there are issues with belt feeding, are there issues with magazine feeding inside of a AR/XCR platform of the 6.5?

cheers,

As for belt feeding, good question, some talked about how fat the cartridge is and how it could be a problem for belt feeding, no hard data whatsoever... As for feeding in an AR and XCR, should be fine as long as the feedramps are cut correctly for this caliber, it seems that M4 feedramps are a no-go on this subject, seems to be complicated though...
 
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