Need Help! Building A New AR Is It A 6.5 G Or A 6.8 SPC

Those "bad generalizations" are taken directly from the original designers goals. They succeeded quite well. Even the antecedent cartridges were tilted in the same direction: The .30 Remington was designed for a self loading deer rifle competing against the .30-30 Lever action. And the 6mm PPC was the origin of the 6.5Grendel, a long distance precision target round.

The generalizations are quite accurate, what some cry foul about is not trying to use the cartridges in "off label" applications. You can, just expect you're not applying them in their window of optimum performance. They will be compromised and not function to the same degree.

Case in point, the 16" or shorter use of 6.5Grendel. Carbine applications are for short range use - not 600 to 1000m targets. Since the high BC bullets don't travel as far in the typical 350m shooting that carbines do, they don't travel far enough to "save" the energy and have it down range. It's a mistaken notion to think they deliver more energy at close range - they don't have it. They simply lose less at longer ranges.

What you wind up with is a compromised design that runs middle of the pack, not the ballistics trumpeted by fanboys as "superior" to the .308. That cartridge would do as well in a 16" barrel, if not better. The disadvantage is that it would still be 1.5 pounds heavier and have some serious muzzle blast.

There's another generalization - short .308s are heavy and noisy. While anyone can nitpick a generalization, they exist for a point - to communicate information in a shorthand way about something.

A generalization is usually considered "bad" because someone can't abide that it says something they dislike. Not necessarily that it doesn't apply.
 
Here is the real data from AA:
Lapua 123 gr. Scenar...at 1000 yards...

24" barrel: 1300 fps
19.5" barrel: 1270 fps
16" barrel: 1226 fps
14.5" barrel: 1189 fps

SO...
nearly 10" of barrel length, and only 111 fps lost...

For those of you that don't have your calculators, supersonic velocity is 1125 fps. So, even from a 14.5" barrel, the 6.5 Grendel can remain supersonic past 1000 yards.

Bullet drop goes from 215 to 262... so, just dial up some more elevation.

Is a 24" barrel better? Sure... Do you need it? Absolutely not.

http://www.alexanderarms.com/images/pdfs/grendel_ballistics.pdf
 
"tirod", I see you are still spreading your biased internet BS and misinformation, you just don't learn or you are not concerned with FACTS AND TRUTH!


"Since the high BC bullets don't travel as far in the typical 350m shooting that carbines do, they don't travel far enough to "save" the energy and have it down range. It's a mistaken notion to think they deliver more energy at close range - they don't have it. They simply lose less at longer ranges."

As usual you are completely WRONG...

FACT, a high BC bullet has an advantage at ALL RANGES. From the moment the bullets leave the muzzle, a lower BC bullet WILL start slowing down faster than a high BC bullet.

As I said to you before, using the SAME RELIABLE source, using the SAME equipment, the SAME methods and the SAME procedures is the only fair way to compare the 6.5 Grendel and the 6.8 SPC.

Using that SAME reliable source...

FACT, although the 6.8 SPC has a 50 fps higher muzzle velocity, by JUST 100 yards the Grendel has a 50 fps advantage. The Grendel catches up to the 6.8 right at 75 yards.

From a 14.5" barrel the 6.5 Grendel will shoot a 100g bullet 2550 fps MV.
From a longer 16" barrel the 6.8 SPC will shoot a 100g bullet 2600 fps MV.
Again from a 14.5" barrel the Grendel will shoot a 129g bullet at 2250 fps MV.
And from the 16" barrel the SPC will shoot a 130g bullet at 2300 fps MV.

And remember, due to the high BC that tirod apparently does not think is important, at less that 100 yards the Grendel has a higher velocity.

Have a problem with the above FACTUAL data? Argue with Hornady, not me. Data is directly from their new 8th edition pages 238-330 and pages 363-365.

Another FACT, regardless of what the wanna-be experts say, the Grendel does this with a SHORTER barrel not the 20" or longer barrel they claim is needed.


"What you wind up with is a compromised design that runs middle of the pack, not the ballistics trumpeted by fanboys as "superior" to the .308. That cartridge would do as well in a 16" barrel, if not better. The disadvantage is that it would still be 1.5 pounds heavier and have some serious muzzle blast."

Duh... "tirod" please check the OP. The question was about the 6.5 Grendel, .264 and 6.8 SPC. Check again, nowhere does he ask about the .308W.


"The confusion starts when it's assumed the 6.5 will perform the same in a 16" barrel or shorter."

Yes, the Grendel will perform better out of a longer barrel but FACT, as shown above, out of a SHORTER barrel the Grendel virtually ties the 6.8 SPC from the muzzle to 100 yards. After that the 6.8 just falls further and further behind the Grendel.

Add a longer barrel to BOTH cartridges and the 6.8 gets a small increase in velocity. The Grendel has a larger increase in velocity.


It is hard if not impossible to turn a short range cartridge into a long range cartridge.

It is far easier to turn a long range cartridge into an ALL RANGE CARTRIDGE.

For normal hunting ranges, out to maybe 200 yards, there really is not much difference between these 2 cartridges. Why choose a "short range" cartridge when for the same price you can have a short, medium and long range cartridge?

One cartridge that can do everything the 6.8 does plus FAR MORE at "all ranges"...

T.
 
Yeah, I know. I guess, I just like to keep them honest, for the sake of the newbies. :)
Funny, he didn't mention 6.8 - 120gr SST. It would be interesting to compare the 120gr SST max load & the 123gr G load out of a 16" barrel.
Hey, 6.8 will ring steel at 1k & kill deer out to 350-400 with spec II or 6.8x43 & shooter abilities.

The G does punch paper better past 500yrds with a 22-24" barrel better though.
 
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If the OP is going to be building a 6.5 in a 20+ inch barrel then wouldn't he be better served by a rifle length gas system? Keeping the gas behind the bullet without being relieved through the gas tube for a longer period of time would result in higher velocities. If you are going H-Bar and 20+ inch barrel and really trying to wring out accuracy then I'd ditch your middy gas system and head straight for a rifle length gas system.

It is my opinion that a Heavy barrel isn't needed. A quality mid profile will be just as accurate unless you are planning on rapid fire however 1000 yards+ and rapid fire seldom go together. Heavy barrel is just added weight in my mind but hey, as long as you like your rifle that's all that matters.
 
6.5 vs. 6.8

"quoting the worst possible 6.8 specs is typical from people who drink the Grendel Kool-aid."

Acc371 and bedlamite if you take the time to actually read my post, at least attempt to COMPREHEND what was written.

The "best" load for neither cartridge was "picked". These were the only loads in the Hornady manual with the same or close bullet weights.

The only way for fairly and honestly comparing any cartridges is to use the SAME RELIABLE source, using the SAME equipment, the SAME methods and the SAME procedures.

You have different figures for the 6.8 SPC? Is it from the SAME UNBIASED, RELIABLE SOURCE?

Of course not, that is why you say there is data but did NOT show comparative data or back up your statement!!!

Another advantage of using data from a source such as Hornady which has data for and loads both cartridges, is that the ammo makers are notorious for being overly optimistic about actual muzzle velocity. The figures I showed are what can honestly be expected especially if you reload.


"Funny, he didn't mention 6.8 - 120gr SST. It would be interesting to compare the 120gr SST max load & the 123gr G load out of a 16" barrel."

Sounds like it is YOU who is picking and choosing loads to make the cartridge you prefer to look its best.

Show me where the 120g SST is shown in the Hornady Manual.

Show me the source with page numbers for this comparison from any, SAME RELIABLE SOURCE.

Again, of course you can't do any of this can you? You can only make unsubstantiated claims.


"Yeah, I know. I guess, I just like to keep them honest, for the sake of the newbies."

Before you question "the honesty" of someone who provides a RELIABLE SOURCE and page numbers, you should look at your own motivation for challenging FACTS as shown is the Hornady Manual with nothing but internet wanna-be BS.

Stop throwing your tantrums because someone else's toys are better than yours (and in this case FAR better).

T.
 
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Contrary to belief even a 6.5/6.8 bullet isn't even powerful enough for a mans basic needs, yes it may kill a ground hog but passed 150yrds it gets a bit iffy.

Don't even think about home defence with it, your better off throwing a hammer.

You need to get something in 7.62mm, it does make a lick of difference what case you've got behind it, it don't matter.

In fact get an AK47, it will penetrate 1" of steel at 300yrds.
And if you reload it with 30cal SMKS get .5moa, the 30cal projectiles are a bit small for the rifling but thats what makes it so accurate.
 
Grendel "Kool-Aid"....???
Are you for real?

That cartridge is everything it's "hyped" to be- and more.

The 6.8 SPC is not even close when it comes to long range- and that's the point of this discussion.

Even at only 500 meters, the 6.8 has dropped to 1470 fps while the Grendel is still humming along at 1797...

Who's drinking the Kool-Aid here?

I can find unbiased article, after article, after article...

http://airbornecombatengineer.typepad.com/airborne_combat_engineer/2006/04/65_grendel_vs_6.html
 
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Unbiased article after article...

I started this thread because I knew little about either round other than a few articles that I had read. The old saying just ask on a forum because everyone is an expert, falls in to play here. While many of you are experts, well... you may all be, I think that this anology sums up my question... 6.5 or 6.8?


Why people are still debating this is beyond any comprehensible grain of understanding. 6.8SPC is a DECENT round compared to 5.56 but severely overshadowed by 6.5G in EVERY regard. I don't own either, I don't care who uses them. I'm an educated person that knows you can't argue against facts because you'll never win. Facts are solidified by testing and proof. Now, originally I WAS a advocate of the 6.8SPC and nothing could change my mind because when compared to 5.56 is offers more energy at most any range. And although 5.56 is bashed a lot, it is a decent round as I've done many of my own ballistic tests at varying distances on various objects and materials and have been surprised at what it CAN do.
The US Military will basically NEVER swap out the 5.56 M4, M16, and their variants for another cartridge size. Accept it. Do they need to? Yes, absolutely. Ask anyone who's been to Iraq...Ok, not anyone but those with actual real experience. They will tell you that it is NOT all CQB distance engagements and many times they were shooting their weapons at ranges of 800m or more with NO clue if they could even reach out that far and do any damage. At that distance (800m and beyond) the 6.5G starts to outpower and range even the 7.62 nato and depending on the round...is still supersonic out to 1200 yards. A round that is supersonic at that distance will absolutely have plenty of CQB power. Try shooting a human size target at 800m+ with an M4 with a Red Dot or better yet...Iron sights. ACOG, not as bad.
Now look at ballistic charts of the 6.8 in comparison to 6.5G and 7.62N. The 6.8 falls like a ton of bricks and loses it's steam very fast. It has absolutely horrible ballistics when it comes to range and energy. And if you think your enemies are always going to be in close quarters then you just don't live in a real world.
Also please take note of the Accuracy of the 6.8SPC round as it also heavily lacks compared to 6.5G. If anyone wants to still argue about the two rounds then it is clear you; A.Can't accept facts. Every type of test has been done and not in one of the tests did 6.8SPC outperform 6.5G. Or B.You can't accept Facts, reality, and you have a major obsession with the 6.8 that resembles that of stalker...you just can't let it go. I honestly don't care what rounds are designed in what size or who uses what. Shoot what you want to shoot and enjoy shooting, regardless of Caliber. I don't wish to hear any responses that are argumentative. There is nothing to argue. I've shot both rounds from a 16 inch barreled AR-15. They're both fun, but side by side comparison from 100yards to 600 removed any and every doubt from my mind about which is better.
 
There are some calibers that, for whatever reason, don't get the attention that's due them.

First one that I discovered when looking at a long range target caliber was the .260 Remington. Although it's now quite "in vogue" with the long range crowd, it never caught on, despite it's superior ballistics. For whatever reason, Remington dropped the ball...

When my son wanted to build his first AR- in a "different" caliber- he told me...I too looked at the 6.8 SPC. But there was no comparison. When I got my first look at the 123 Amax bullet, I knew why- it's obvious that despite it's lighter weight, it's BC is excellent. It's amazing to me, as a handloader, that a bullet that long fits into the case without compressing the load. It really is an impressive round- and in the way Remington failed with the .260, I think Bill Alexander, unfortunately, blew it on the marketing end with his baby here.

Like the .260 though, the Grendel seems to only now be getting the attention it deserves.

Now the downside- which will be solved if Wolf delivers on some steel case ammo- is that it's not a plinking rifle like a .223 can be. Even my handloads run close to .50 each- still better than the buck a round for factory ammo.

I'm sure that's part of the reason that the 5.56 still rules.... you can send a couple of hundred rounds downrange without breaking the bank and just plain have fun.
 
6.5 Grendel is the winner!

Acc371, they say there is no cure for stupid. So why do you insist on continuing to proving it?


"So, Wilson Combat is not a reliable source?"

It is obvious that you are unable to COMPREHEND what was written or like the OP said, "Why people are still debating this is beyond any comprehensible grain of understanding. If anyone wants to still argue about the two rounds then it is clear you; A.Can't accept facts. Every type of test has been done and not in one of the tests did 6.8SPC outperform 6.5G..."

What don't you understand about the words, SAME RELIABLE SOURCE?

Do you not understand that Wilson Combat DOES NOT load the 6.5 Grendel.

Do you not understand that regardless of how reliable Wilson Combat is as a "source", it is IMPOSSIBLE for them to be the SAME source for an ammo type they do not load.


"As for the 120gr SST, I was just thinking it would be an interesting to test the 2 bullets."

So obviously you know nothing, you have no facts, you just want to "pick and choose" a load that you (hope) will be better. As before, no facts, no truth, just what you wish was true.


"But, in the end. It is all mute point."

All is mute except for you. You want to argue against FACTS with your wanna-be internet expert misinformation.


"The thread starter has made a decision."

Acc371, do you have ANY clue why the OP decided on the 6.5 Grendel? Did you READ and try to COMPREHEND anything at all the OP wrote?

Well I did. He went with the Grendel because he is educated and is convinced by FACTS and the truth and not by the ranting tantrums of someone spouting misinformation.

T.
 
Your rant is funny!!! But detracting.

I don't care if WC loads Grendel or not.
I was pointing out & Belamite caught it. You used a standard loaded cartridge loaded by Hornady to show top velocities to prove you point. I was just showing you a factory load with higher velocity than the one you used. To show the velocity you used for the 6.8 is not the highest velocity of the cartridge in a factory load. Your fact is based on a cartridge used loaded for both SAAMI & Spec II.
As shown in the link - 6.8 SPC II = 16" barrel 110gr 2700fps (16" barrel 95gr -2850fps)

I'm not even going to bother replying to the 120gr SST. :rolleyes:

FWIW I did say the 6.5 does punch paper better than the 6.8 at 1k in my original post.:p
 
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I would go with the 6.5g for distance especially if your trying to go all the way out to 1000yards . Ive read the 6.8 is a good round for about 500yards. My neighbor teaches long range shooting, as well as other combat courses. I was talking to him about the 6.5g, he told me that he knew about 14 people who once owned a 6.5 and ended up selling/ trading them back for another caliber, mostly .308. out of those 14, 13 had already gotten ride of there 6.5's. Like i said most of them went back to the .308. But to answer your question i would go with the 6.5.
 
Just found some new info. on the Grendel

This should quiet some of the complaints from the wanna-be experts but... It won't!

Thanks to TimW77 for bringing this to my attention! ;)

"Alexander Arms Announces: The 6.5 Grendel® Is An Official SAAMI Cartridge

The Sporting Arms and Ammunition Manufacturers' Institute ("SAAMI") has adopted the 6.5 Grendel as an official SAAMI cartridge. As a result of the cartridge's official recognition, ALEXANDER ARMS® will relinquish the trademark "6.5 Grendel."

Bill Alexander states: "One of the primary purposes of trademarking the name was to protect the integrity of the design. With the adoption of the 6.5 Grendel cartridge standard by SAAMI, the design is now protected and any confusion in the marketplace as to the specification of the cartridge has been eliminated."

SAAMI's formal adoption of the design specifications for the cartridge has led ALEXANDER ARMS® to announce that it will relinquish its federally-registered trademark and that "6.5 Grendel" is to be the common commercial name for a cartridge that adheres to the specifications adopted by SAAMI.

ALEXANDER ARMS® is proud that a cartridge of its design has received this important designation and is pleased to take this important step in the continued market development of this breakthrough cartridge, which is perfectly matched to the AR-15 platform.

For additional information, contact:
Alexander Arms
wayne@alexanderarms.com
540-639-8356

"ALEXANDER ARMS®" is a registered trademark of Alexander Industries, Inc. All rights reserved."
 
Indi said:
I was talking to him about the 6.5g, he told me that he knew about 14 people who once owned a 6.5 and ended up selling/ trading them back for another caliber, mostly .308. out of those 14, 13 had already gotten ride of there 6.5's.

Were you thinking "6.8" and wrote "6.5"...?
Just clarifying your comment after your remark about the 6.8.

I don't hear of many shooters that are unhappy with the 6.5 at long range...the 6.5 Creedmore developed by Hornady is yet another tack-driving offering...
 
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