Home Forums Hunting & Shooting AR and Tactical Rifles 6.8 vs. 7.62x39 vs ???

Widening the page out makes it difficult to follow. Just sayin'...

is the beowulf interesting? Must be since I drive one... grins....

I run 223 right at 60kpsi and have for years. The platform is very capable of handling that. The question becomes the bolt lugs possibly, but beyond that, I see no reason to limit pressures other than the vessel, this vessel is plenty strong. To not load them ALL to that same limit, leaves something on the table which could be a plus IMHO

After shooting the 6.8 and 7.62X39 I am much more impressed with the 6.8. IMHO the 6.8 is head and shoulders above the 223. I have zero experience with the 6.5 Grendel.

Did I say that I really like the 6.8

jwp, did you load the 7.62x39 with good bullets and decent pressure or stick with surplus ammo?

What did you load in the 223?

Just wondering.

I really like John Barness most recent lethality power formula:

This is some tough math so the 6.8 aficionado's may need to use a calculator.

"My more recent killing power formula is the 90/9/1: 90% is bullet placement, 9% is bullet performance, and 1% is headstamp."

always did wonder how my 32-20 killed every deer and pig/javelina it was ever aimed at.....

And still wondering how my civil war smoothbore is going to kill with a 19ga round ball and 60 of 2F, but something tells me it probably will do fine....

They can't sell marksmanship...

I'm planning a Cape Buffalo safari in a few months. You can use my .22 Hornet. You up for it?

I know its not directed at me, but I'd have zero qualms on a buff with a 22 hornet. Let me pick the bullet and then allow me to choose my shot, I'd be just fine and meat on the ground.

Just like using a 223 OR a 6.8, neither are magic or powerful enough that you can take any shot presented.

Of course it doesn't hurt that I'm nuts enough the 2 things I have on my list that I'll never be able to afford are a buff with a bow and a brownie with a bow. I'd like an nyala, but don't care how I'd get that for some reason. And of course Africa is the last place I'll spend money if I had it, prefering to hunt and support our game in the US instead. But if I hit it big ever... I could manage Africa then...

Ouch touched a nerve! Yes sure I would go with you and take the hornet (if given the chance). Barness makes a good point, 90 percent shot placement, 9 percent bullet, and 1 percent headstamp, I do believe the man has killed more big game than either of us!

(I personally think its 85% shot placement, 14% bullet and 1% headstamp!)

One thing I like about my 7.62 x39 over my Grendel is the ability to load a wide variety of "Hunting" bullets from the fast light weight 110gr bullets at 2650+ fps to the devastating 150gr Hornady 30-30 RN bullet at 2200-2300 fps.
There are very few 6.5 Hunting bullets that fit into the Grendel's velocity/weight range. The Nosler BT (Junk IMO) and the Barnes TSX/TTSX, that's about it.

For a Hunting rifle, if I had to choose one over the other I would take my X39.

I choose the 6.8 and very happy with it

"I'm planning a Cape Buffalo safari in a few months. You can use my .22 Hornet. You up for it?"
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Question is, is your 6.8 enough of a jump to take it?

See, I'm not nuts enough to make that claim.

Barsness's quote is taken out of context IMO. It assumes relatively similar ballistics.

LOL, I had to put down a cow once with a 223. It worked but she looked like a mad elephant and the 223 a bb gun but it worked.

From that experience, I jump from the 223 class to the 308 class and from there it'd get really intersting...

How can it be out of context really, when its typically the indian and not the arrow?

Assuming good projectile choice, then its shot location or pass. Having the ability to pass the shot is a major thing, EVEN if the ability of the round and projectile are up to the task.

Probably why I've been able to kill up to just over 400 pound wild hogs with a ruger MK2 22 pistol... And I have shot a LOT of pigs after friends that were convinced they needed something big for pigs... like 06 or even bigger, would shoot first.... one morning we had 2 pigs out just over 200 pounds... buddy had to take 45-70 cause they are mean and tough you know... we snuck in to about 30 yards from them and I says wait till I'm good, I got the 22 out and loaded, and ready.. I'm good. He picks the shot goes bang. The first pig hit runs off. The 2nd one stops about 30 feet further off and gets a bullet to the lungs... We go get his, drag it down to the road, go back to camp and gut it and then go find mine, about 75 yards or so away dead from a lung shot.

Best choice of rounds? Nope. But where exactly do you draw the line?

And no where in here am I saying there is a thing wrong with the 6.8 either. But what it takes, and what you want to use are 2 different things.

JB was certainly not taken out of context relative to the puny cartridges we have been discussing.

Someone mentioned upping pressures in the 7.62x39, let me give you something to consider. The M43 cartridge (7.62x39) is a radically tapered case and that translates to bolt thrust of magnitudes greater than the nearly straight walls of the 6.8 SPC. On paper, the bolt thrust is pretty close from a mathematical standpoint. But that�s on paper. Many of the straighter walled cartridges have very little ACTUAL bolt thrust at all. PO Ackley proved this with his Winchester 94 with the locking block removed; fired it, and the bolt stayed closed (I believe that was with a completely straight wall AI case though). The more taper you have, the more actual bolt thrust you get, and therefore the more true abuse to the locking lugs. So perhaps loading an additional 10kpsi is fine, but you need to know that it does have an effect, even if you can�t see it. With a clean chamber, you can take the extractor out of a 7.62x39 gun and it will still be around 90% reliable. I really don�t see why someone would feel the need to up the pressure another 10kpsi, for what it was created for, the M43 cartridge performs rather well.

The 6.8 is an excellent cartridge, possibly the most �ideal� assault rifle cartridge out there. It�s clearly better than the M43 in most categories except cost. I tend to think the 6.8�s minimal taper is much better suited to the straight, then curved magazine of the AR than the sharply tapered M43. So even though the M43 has a bunch of reliability built into the design, it�s dependent on a magazine optimized for the cartridge shape such as the AK magazine (which is the best magazine in the world). Since you can�t use an AK magazine in an AR, I�d either stick with the 5.56 or go to the 6.8.

6.5 Grendel is a slick cartridge also and ballistically beats the 6.8 in most categories, but it has reduced magazine capacity, and you really have to get the mag right for perfect functioning. I really don�t know how well a 6.5 would do in harsh environmental conditions using a case that fat in a magazine that skinny.

One has to draw the line somewhere, my joking reference to the .22 Hornet and a Cape Buffalo drew at least one "maybe".

You can kill almost anything with any cartridge, the sliding scale of differences comes in margin of error. Yes, you can kill a Cape Buffalo with a .223, but you're going to have to pick your shot wisely and if you don't have your choice of shot angles, you might get stomped into a mud puddle.

Will a 7.62x39 kill just about anything a 6.8spc will? Absolutely.

Will a 6.8spc using optimal bullets at SAAMI pressures deliver flatter trajectory, less wind drift and possibly a little more penetration at distance, than a 7.62x39 using optimal bullets at SAAMI pressures? Yes, that's a fact of physics.