6.5 Grendel vs 6.8 SPC Vs 100 Hogs

[Harpoon1]

https://youtu.be/d1eSTKZGP_I

[Clintster]

Perfect for my afternoon work-break! Very nice.

[tdbru]

good points.

man, you really must have a feral pig problem, that is a LOT of feral piggies tearing up the place.
-tdbru

[sundowner]

nice video thanks for sharing .

[grendelnubi]

I had high hope's for the 120 NBT performance since I was considering using it this year but obviously it didn't perform as well as the others. Regardless I have decided to use the 120 Gold Dot for this years deer season. Hogs are tough critters and a good baseline. Thanks for the video.

[BluntForceTrauma]

Good stuff! My take aways?

Terminal performance is about equal at the 100 yards and under in the test.

Moving targets are hella hard to hit!

Every time the shooter had time to carefully place his first shot on a relaxed hog, they dropped. After the first shot and they started running and the adrenaline was up and the shot placement was more or less random, terminal performance was a roll of the dice.

Shot placement is still king.

[Double Naught Spy]

good points.

man, you really must have a feral pig problem, that is a LOT of feral piggies tearing up the place.
-tdbru

That is Ranchtop1833's video. He is up in southern OK. I have hunted with him a few times. He hunts multiple properties over a fairly wide area. Yes, they really have a feral hog problem up there, just like much of the south.

[Fess]

Good stuff! My take aways?

Terminal performance is about equal at the 100 yards and under in the test.

Aw heck! Where's the fun in that! Half the fun of following the Grendel and SPC websites in the early days was to read the mud-slingin' and name-callin' between the two.

I even remember when Wikipedia froze both the Grendel and SPC entries because there was so much activity from the opposing camps going onto each other's site and changing data to make their own favorite cartridge look better!

[Double Naught Spy]

Sometimes, reality isn't fun. It is just reality. Two similar sized bullets of similar weights and similar makes going at similar velocities when striking the target are going to produce similar results. At typical hunting distances inside of 200 yards, most folks aren't apt to see any significant terminal/lethal differences between the two.

[Fess]

In all seriousness, both cartridges are good for normal hunting distances. The choice of bullets and skill of the shooter are really the most important factor in hunting situations. Compromises were made with both to get them to fit into a platform (AR15) that was designed for a smaller diameter cartridge. The 6.5 Grendel allows a longer ogive, which gives it an advantage when someone wants to use sleek, high-BC bullets. This is especially useful in longer-range target shooting. The designers of the 6.8 SPC made the tradeoff of using shorter, stubbier-ogived bullets to allow a somewhat smaller-diameter, but longer case. This gives it a slight feeding and bolt-strength advantage when used in an AR15-based weapon. The 6.8 SPC has a slightly more robust case (with thicker case walls near the base) which causes it to lose some capacity but makes it a little more tolerant of overpressure. Compromises.

[Double Naught Spy]

Compromises were made with both to get them to fit into a platform (AR15) that was designed for a smaller diameter cartridge.

True, sort of. People like to talk about compromises of ammo, but in reality, EVERY cartridge is a compromise to others, just pick your criteria. There isn't one that does everything. Much of the fighting between the 6.8 SPC and Grendel people seemed to be between folks cherry picking the criteria that favored their perspectives. If you select for this trait, then you give up something on that trait. You can't get around it.

Back in my defensive pistol competition days, I used to make fun of the guys that always seem to want to have the lightest pistol shooting the highest velocity ammo with the least recoil making the biggest holes where the pistol and ammo were both dirt cheap. The gun was also 100% totally reliable with the 'fastest sights' day or low light condition, holding the most ammo, while being the most concealable. Did I mention how this gun was supposed to be at the pinnacle of accuracy?

Everything is a compromise. It is a given.

[Fess]

Everything is a compromise. It is a given.

That's true, of course, but this is a particularly interesting case because the designers of the 6.5 Grendel and 6.8 SPC both decided to create "improved" cartridges yet fit them into the AR15 platform. The magazine well, bolt diameter and barrel extension were all designed for a smaller diameter, less powerful cartridge. This forced more compromises than usual. Things would have been very different if more changes to the AR15 were permitted (larger dia bolt and barrel extension, wider mag well, etc)*.

Although both new cartridges were designed to be improvements over the 5.56x45, they were designed to do different things. The 6.5 Grendel was designed to be more of a General Purpose Cartridge (GPC), effective at ranges approaching 1000m and effectively taking the place of the 7.62x51 for foot soldiers. It was also intended to be a competitive target round at 600+m. The 6.8 SPC, on the other hand, was designed to be an improvement on the 5.56x45, especially at close quarters out of a short barrel, but did not extend its effective range as much (500-600m, max).

To achieve the longer effective range, the designers of the 6.5 Grendel decided to use a long ogive to utilize sleek, high-BC bullets.** Because it had to be roughly the same length of the 5.56x45, this resulted in a significantly shorter and larger diameter case. The use of a case with a base diameter of 0.441" vs the 0.378" of the 5.56x45 resulted in weaker bolt lugs and lower allowable chamber pressure as well as less than optimum feeding though the AR15's magazine well.

The developers of the 6.8 SPC, on the other hand, accepted a shorter ogive in order to permit a longer, slightly smaller diameter case (0.422") when compared to the Grendel. Their choice of compromises were to give up some long-range efficiency in order to get better feeding though the AR15's magazine well and allow a higher chamber pressure. They also chose to use thicker case walls near the base to make it less sensitive to overpressure, this slightly reduced propellant capacity.

Photo of 6.8 SPC vs 6.5 Grendel (posted on an earlier version of this website)
6.5-Grendel-vs-6.8-SPC-Cutaway-223x300.jpg


*There have been other variants of the AR15 that HAVE done this, including the Colt CM- and CK-901, various models of Olympic Arms, especially the WSSM models, some AR Performance AR15-based models that used a 0.473" diameter case, and some current CMMG models.

** The 6.5 Grendel was designed to use Lapua Scenar 6.5mm, 123 and 108gr bullets, two of the Highest BC bullets available in their weight classes at the time.

[myrifle]

That's true, of course, but this is a particularly interesting case because the designers of the 6.5 Grendel and 6.8 SPC both decided to create "improved" cartridges yet fit them into the AR15 platform. The magazine well, bolt diameter and barrel extension were all designed for a smaller diameter, less powerful cartridge. This forced more compromises than usual. Things would have been very different if more changes to the AR15 were permitted (larger dia bolt and barrel extension, wider mag well, etc)*.

Although both new cartridges were designed to be improvements over the 5.56x45, they were designed to do different things. The 6.5 Grendel was designed to be more of a General Purpose Cartridge (GPC), effective at ranges approaching 1000m and effectively taking the place of the 7.62x51 for foot soldiers. It was also intended to be a competitive target round at 600+m. The 6.8 SPC, on the other hand, was designed to be an improvement on the 5.56x45, especially at close quarters out of a short barrel, but did not extend its effective range as much (500-600m, max).

To achieve the longer effective range, the designers of the 6.5 Grendel decided to use a long ogive to utilize sleek, high-BC bullets.** Because it had to be roughly the same length of the 5.56x45, this resulted in a significantly shorter and larger diameter case. The use of a case with a base diameter of 0.441" vs the 0.378" of the 5.56x45 resulted in weaker bolt lugs and lower allowable chamber pressure as well as less than optimum feeding though the AR15's magazine well.

The developers of the 6.8 SPC, on the other hand, accepted a shorter ogive in order to permit a longer, slightly smaller diameter case (0.422") when compared to the Grendel. Their choice of compromises were to give up some long-range efficiency in order to get better feeding though the AR15's magazine well and allow a higher chamber pressure. They also chose to use thicker case walls near the base to make it less sensitive to overpressure, this slightly reduced propellant capacity.

Photo of 6.8 SPC vs 6.5 Grendel (posted on an earlier version of this website)
[ATTACH=CONFIG]18327[/ATTACH]


*There have been other variants of the AR15 that HAVE done this, including the Colt CM- and CK-901, various models of Olympic Arms, especially the WSSM models, some AR Performance AR15-based models that used a 0.473" diameter case, and some current CMMG models.

** The 6.5 Grendel was designed to use Lapua Scenar 6.5mm, 123 and 108gr bullets, two of the Highest BC bullets available in their weight classes at the time.

Actually l. Bill has stated several times his primary reason for developing the grendel was a better ar15 cartridge for deer hunting. He is even on film stating that fact.

And the barrel extention is the same used for 556 barrels no matter if it's on a grendel barrel or 6.8 spc barrel.

I'm still trying to break my first grendel bolt under normal useage. Have broken a few but was ententaly running hot handloads too do a destruction test.

[biodsl]

Everything is a compromise. It is a given.

Or as Thomas Sowell has said "There are no solutions. There are only trade-offs."

[lazyengineer]

I like them both, and pragmatically consider them interchangeable in performance - mostly. For me (and this is me), the reason Grendel edged out the good 6.8 round is the
-longer legs at distance (at the time, I could go to CCC, and bang gongs out to 1000 to even 2000 yards, which is seriously fun - until they closed [darnit!]).
-inexpensive steel; allowing this round to shoot longer than 6.8, and also be fed at literally 1/4 to 1/3 the cost of 6.8.
-As a reloader, I can feed Grendel with 7.62x39 brass, which I do sometimes see on the ground.
-As a 6.5 Creedmoor shooter (I skipped .308 entirely), 6.5 Grendel allows some commonality of components and equipment as a reloader.

The 6.8 does offer a little higher pressure rating, which I like. -I have a feeling those components have a longer life, since the bolt-head is naturally going to be stronger, and the extractor can have more meat to it. And I like 6.8's very slightly better 100 yard performance. But in the end, this video does a great job of quantifying that while 6.8 does in practice have better downrange performance, that improvement is extremely marginal, and takes a large body of data to even start to notice.

The reason I like 6.5 Grendel more than 6mm ARC or .224 Valk, is I believe the heavier/fatter down-range performance of 6.5 matters. I am of a bias (without a lot of data to really back it up), that the same video made with 6mm ARC or .224 Valk, would have a very different result, than the one comparing Grendel to 6.8.

This is why I love 6.5 Grendel - I consider it the ultimate optimized round with excellent performance at everything. It's a high-action combat round, it's a long range round, it's a precision round, it's a solid hunting round, it can be a very cost-effective round, it's a round that supports a long barrel life, and it all fits in a small frame AR15. Any deviation from the 6.5 Grendel form-factor to improve any one of those, comes at a cost from the other capabilities that I don't find an acceptable trade-off.

500 yards:


That said, 6.8 is so close to 6.5 Grendel, that it will have similar performance as well, until you start getting out there to 600 yards and beyond. And, I sometimes get out there to 600 yards and beyond.

To me, 6.5 Grendel is... the optimized second derivative (some will understand that odd perspective and turn of phrase). If I ever have the chance to have beer with Bill Alexander - I will!