This -><- close to choosing 6.8 SPC vs 6.5 grendel

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06-17-21, 23:02
titsonritz

I've been looking at 6mm ARC.
06-18-21, 09:14
TheJawn

Quote:

Originally Posted by grizzman

I've got one of each. I use E-Landers for 6.5 and PRIs for 6.8, and haven't had any problems with any of them.

The 6.8 might be more popular for the hunting crowd, but any differences between the two on game should be minimal. The 6.5's increased BC can't be ignored, if the use case involves mid to long distance shooting.

Inside 200m, with 90gr bullets, with any barrel length, performance on hogs is not similar, it's identical.

If you want a paper puncher get a 6mmARC from... Faxon? I don't know who else is selling ARC barrels.
06-18-21, 10:24
Red*Lion

Quote:

Originally Posted by TheJawn

Inside 200m, with 90gr bullets, with any barrel length, performance on hogs is not similar, it's identical.

If you want a paper puncher get a 6mmARC from... Faxon? I don't know who else is selling ARC barrels.

Here a 4 others that sell 6mm ARC barrels just doing a quick search.

https://www.precisionfirearms.com/m8...more%20rows%20

https://www.opticsplanet.com/helix-6...10070301008005

https://www.shawcustombarrels.com/sh...ory/6mm-arc/28

https://compasslake.com/product/6mm-...lein-4-groove/
06-18-21, 14:10
Steve_in_Allentown

Quote:

My conclusion, as an all-around cartridge, the 6.5 Grendel is the clear winner.

There seems to be a difference of opinion in this matter. I suspect there are a ton of posts here debating the two cartridges and we will not settle the matter here. I say, to each his own. The two cartridges are for all practical purposes nearly identical in terms of exterior ballistics. I give the edge to the 6.8 because of it's better track record of reliable feeding and lack of catastrophic bolt failures. My 18" ARP barreled 6.8 easily does < 1 MOA using factory ammo.

https://www.ar15performance.com/home

Quote:

Originally Posted by Harrison

The 6.8 SPC II, Best all around AR15 cartridge.

Defensive and Hunting the 2 largest sectors

The 6.8 SPC is the #1 choice for hunting deer and hogs with an AR15.

Using factory ammo the 6.8 is approximately 100fps faster than the Grendel using the same weight bullet and same length barrel. Out to 175 yards the 6.8 has more energy with 110 and 120gr loads. A 16" 6.8 loaded with factory Hornady 120gr SSTs has enough velocity to expand and energy to take deer and hogs at 400yds. The Grendel horde likes to say the 6.8 is a short range hunting round and the Grendel is long range . . . BS. Load a 130gr Berger Classic Hunter (BC .497), 130 Speer or Sierra BT in the 6.8 and it will push it to the same velocity as a 123gr 6.5 Grendel. The BCs are very close so the drop and drift will be very close way past ethical hunting distances and the 6.8 bullets actually expand as designed.

There are defensive bullets like the 90gr Gold Dot, and several FMJs. There are bonded hunting bullets like the 100 and 110 Accubond, premium solid copper bullets Barnes 85 TSX, 95TTSX, 110 TSX, Cavity Back 100, and 120 MKZ and Hornady 100 GMX.

The 6.8 mags feed better. The bolts and extractors are stronger and more durable than [those used for] Grendel based cartridges.
06-18-21, 19:16
Red*Lion

Quote:

Originally Posted by Red*Lion
My conclusion, as an all-around cartridge, the 6.5 Grendel is the clear winner.

Quote:

Steve in Allentown said....There seems to be a difference of opinion in this matter. I suspect there are a ton of posts here debating the two cartridges and we will not settle the matter here. I say, to each his own. The two cartridges are for all practical purposes nearly identical in terms of exterior ballistics. I give the edge to the 6.8 because of it's better track record of reliable feeding and lack of catastrophic bolt failures. My 18" ARP barreled 6.8 easily does < 1 MOA using factory ammo.

Why did you attribute a quote to me when it is the words of the author of one of the articles that I quoted/posted? I am not trying to convince anyone to agree with me. To each their own. I have had zero feeding problems with Grendel mags and zero problems with bolt failures. Both cartridges are similar to around 300 or so yards and then the Grendel performs better. Hard to get Grendel ammo, but that's why serious Grendel shooters reload. Have and enjoy what you want.
06-20-21, 14:13
Steve_in_Allentown

Quote:

Originally Posted by Red*Lion

Why did you attribute a quote to me when it is the words of the author of one of the articles that I quoted/posted?

My mistake. Apologies.

Since you reload I thought the following written by the guy who runs AR15 Performance might be of interest.

Quote:

Originally Posted by constructor a.k.a. Harrison at ARP

6.8 vs Grendel pressure & warning

We've talked about pressure and the 6.8 vs the Grendel since 2007. While many understand you can not push a Grendel as hard as a 6.8, I don't think many know the real reason why. This photo makes it pretty easy to understand. Internet wide there are lots of assumed reasons.

Some of the real "talkers" say the hoop strength of a 1" diameter barrel is not strong enough for anything bigger than the Grendel at 52,000psi. Well, many have been shooting 6mmBRs and 6BRXs at 60,000psi since 2009. Then just 3 years ago it took a big jump with all of the 308 based wildcats e.g. the 270AR, 7mm VAR, 6.5BRX, and all of them pushed to the limits. So we have easily proven the hoop strength rumor is pure BS started by one company to protect their baby.

Then there is the weak bolt reason. This one is true in a way. Pushing the pressure on a normal mil spec design bolt can cause them to break. There are a few designs that will handle higher pressures. Our 9310 "superbolts" will handle the pressure better than most when the receivers are square. The 750XD bolts I designed last year will handle 60k psi easily. That may fix the weak bolt issue but there is still one thing standing in the way.

At 60,000 psi the brass starts expanding. If you look at the photo below you can see how thin the brass is on a Grendel case and just how far down that thin brass is compared to the 6.8. That is exactly why we can run the 6.8 so hard without the issues seen in the Grendel brass. The fact that Alexander Arms changed the bolt face depth to .135” to allow for a thicker rim on the Lapua case did not help. That moved the thin case wall another .010” out of the chamber leaving it unsupported. I've tried to push the Grendel as far back as 2007. As I approach 60,000psi the brass expands into the unsupported part between the bolt face and chamfer at the breech. The Grendel cases start looking like a belted magnum. I had a 6mm Banshee/6mmAR/224 Predator rupture. It blew all of the gases out through the mag. The floor plate was found 30-40yds down range. If the pressure had been just a little higher it would have split the carrier, swelled the lower and could have sent a lot more chunks of metal in my direction.

So now with the 224 Predator and 6mm Predator and the 750XD bolts all allowing higher pressures to be used don't forget the Grendel case is still the weak point. If you see the base of the cases swelling right down to the top of the groove BACK OFF. Watch that part of the case closely. BTW- the new steel case Grendel may allow us to push things a little harder.

https://i.imgur.com/PYt74WI.jpg
06-20-21, 14:42
Steve_in_Allentown

More insight from Harrison. My take away from all the numbers is that the two calibers provide essentially the same ballistics. The differences are definitely there but so small as to be of little practical consequence within 600 yards. My benchrest days are well behind me. A long shot for me these days is 300 yards. If I need to reach out any further than that it'll be with a .308 or 6.5 Creedmoor.

Link to the information presented below: LINK

Quote:

Originally Posted by constructor a.k.a. Harrison at ARP

Most of the time on arfcom and other places we see the Grendel folks comparing the 6.5 to the 6.8 by choosing the best 6.5 bullet and the worst 6.8 bullet or velocity of a 24" Grendel to a 16" 6.8. That is just the stupid games they play and have been since 2007 that I know of. This is comparing a 120gr SST out of a 20" 6.8 barrel to a 123gr SST out of a 20" 6.5 barrel both using Hornady factory ammo. It can't get much closer for comparisons. I am using the G7 BCs found by Bryan Litz of Berger not the inflated BCs used by the bullet manufacturer.

Notice the numbers around the 400yd mark where the bullets start to drop below the expansion threshold.

Test Conditions for both calibers
wind speed: 10mph
wind angle: 90 degrees
zero height: 2.5"
target height: 12"
vital zone radius: 5"

Projectile BC
Grendel: .230 G7
6.8 SPC: .200 G7

Maximum Point Blank Range
Grendel: 310 yards
6.8 SPC: 314 yards

Remaining Energy at max PBR
Grendel: 1017.2
6.8 SPC: 976.4

https://i.imgur.com/lEf9DJs.jpg
06-20-21, 15:17
gunnerblue

Quote:

Originally Posted by Red*Lion

Here a 4 others that sell 6mm ARC barrels just doing a quick search.

https://www.precisionfirearms.com/m8...more%20rows%20

https://www.opticsplanet.com/helix-6...10070301008005

https://www.shawcustombarrels.com/sh...ory/6mm-arc/28

https://compasslake.com/product/6mm-...lein-4-groove/

Proof Research also offers this caliber
06-20-21, 22:37
pinzgauer

One thing to keep in mind is that all the 6.8 SPC figures people like to point to are the so-called SPC-II non-sammi variants. And some of the information being referenced in this thread is from people with a very strong vested interest in selling non-sammi barrels for 6.8. It is very clear to me they are no longer objective sources.

Your common inexpensive SPC from Remington or similar doesn't perform anything like that. And using the hot stuff in a barrel with the sammi throat is a recipe for high pressure problems.

People mention Grendels and bolt life/failure. I've been shooting Grendel extensively since 2008, as has my brother and also some friends. No one I know has ever had a bolt issue. Nor magazine issues.

The bolts do receive more bolt thrust due to the larger bolt head diameter, so do have to be stronger. You could argue fairly there's less margin of error with a grendle bolt than with 5.56. Much less of a difference between Grendel and SPC though.

On the positive side it is very difficult to make an inaccurate grendel load when hand loading. There is a pretty good selection of bullets, all that I need.

Both my brother and I have hunted with Grendel, and my son is starting to. It's a deadly stopper on hogs and deer. And even bigger if you're willing to try though I wouldn't recommend it or 6.8 for longer ranges.

And the ability to get steel case Grendel ammo for plinking/training up until recently was a huge win. It's not super accurate but it's great for 25 and 50 m drills.

Grendel was also designed from the very beginning to be extremely reliable in full auto in both AR and AK platforms. And accordingly is sold for and in use by militaries in the AK platform. It was also designed such that it could be made on the barnul and similar Soviet ammo making machines.

And the last thing is that being able to use 7.62X39 brass was a real advantage when brass was hard to get during the 2008 shortages. One swipe through the loading die and you're in business.

There are enough intangibles to swing the needle to Grendel for me. I can shoot any of them, and if 6.8 had a substantial advantage I would change to that route. But especially if you're a hand loader, Grendel is a very easy pick. I know very few people that went Grendel and regretted it. But I do know some people that went 6.8, but then ended up moving to Grendel.

6mm ARC might be fun for paper at distance, but I really don't want to go that light on projectiles. And if I needed to, Grendel gets awful close. Bill Alexander did used to say that the ideal Grendel bullet weight was 110 to 115, which is closer to 6 mm ARC.

But the Hornady 123 amax and SST were pretty much designed specifically for Grendel, have the same exact BC and can be used interchangeably without changing loads. So I'm very happy with those two projectiles for hunting and target.

The Hornady 123A Max factory loading was extremely accurate. I've shot five shot half inch groups at 100 yd with that in my first grindle which was a 20-in stainless bull barrel. Like I said earlier, it's very hard to make an accurate Grendel's unless you miss-built the rifle.

So yeah, I'm a Grendel fan. There's a lot of intangibles that don't get discussed much that led me that direction. But it's not worth arguing over on an internet forum :-)
06-21-21, 07:11
gunnerblue

Quote:

Originally Posted by pinzgauer

One thing to keep in mind is that all the 6.8 SPC figures people like to point to are the so-called SPC-II non-sammi variants. And some of the information being referenced in this thread is from people with a very strong vested interest in selling non-sammi barrels for 6.8. It is very clear to me they are no longer objective sources.

Your common inexpensive SPC from Remington or similar doesn't perform anything like that. And using the hot stuff in a barrel with the sammi throat is a recipe for high pressure problems.

People mention Grendels and bolt life/failure. I've been shooting Grendel extensively since 2008, as has my brother and also some friends. No one I know has ever had a bolt issue. Nor magazine issues.

The bolts do receive more bolt thrust due to the larger bolt head diameter, so do have to be stronger. You could argue fairly there's less margin of error with a grendle bolt than with 5.56. Much less of a difference between Grendel and SPC though.

On the positive side it is very difficult to make an inaccurate grendel load when hand loading. There is a pretty good selection of bullets, all that I need.

Both my brother and I have hunted with Grendel, and my son is starting to. It's a deadly stopper on hogs and deer. And even bigger if you're willing to try though I wouldn't recommend it or 6.8 for longer ranges.

And the ability to get steel case Grendel ammo for plinking/training up until recently was a huge win. It's not super accurate but it's great for 25 and 50 m drills.

Grendel was also designed from the very beginning to be extremely reliable in full auto in both AR and AK platforms. And accordingly is sold for and in use by militaries in the AK platform. It was also designed such that it could be made on the barnul and similar Soviet ammo making machines.

And the last thing is that being able to use 7.62X39 brass was a real advantage when brass was hard to get during the 2008 shortages. One swipe through the loading die and you're in business.

There are enough intangibles to swing the needle to Grendel for me. I can shoot any of them, and if 6.8 had a substantial advantage I would change to that route. But especially if you're a hand loader, Grendel is a very easy pick. I know very few people that went Grendel and regretted it. But I do know some people that went 6.8, but then ended up moving to Grendel.

6mm ARC might be fun for paper at distance, but I really don't want to go that light on projectiles. And if I needed to, Grendel gets awful close. Bill Alexander did used to say that the ideal Grendel bullet weight was 110 to 115, which is closer to 6 mm ARC.

But the Hornady 123 amax and SST were pretty much designed specifically for Grendel, have the same exact BC and can be used interchangeably without changing loads. So I'm very happy with those two projectiles for hunting and target.

The Hornady 123A Max factory loading was extremely accurate. I've shot five shot half inch groups at 100 yd with that in my first grindle which was a 20-in stainless bull barrel. Like I said earlier, it's very hard to make an accurate Grendel's unless you miss-built the rifle.

So yeah, I'm a Grendel fan. There's a lot of intangibles that don't get discussed much that led me that direction. But it's not worth arguing over on an internet forum :-)

All good points, especially in regards to bolt life. All of bolt failures I've read about with no other mitigating factors seem to stem from using the .125" bolt face depth vs the original (Type II) .136."

Which military/militaries are using the Grendel?

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