6.8 SPC 6.5 Grendal

Status
Not open for further replies.
I made this comparison before selecting 6.5 Grendel. On paper, the ballistics of the Grendel for a given or very similar bullet weight show higher muzzle velocity, the bullets have higher B.C. and downrange they just runaway from the 6.8 SPC. This is true of both comparable ammunition like Hornady Custom with 123 gr. SST vs 120 gr. SST, and it's also consistent with load data. In suppositional theory, the 6.8 bullet is believed to have better terminal effectiveness, but I think this is derived from comparisons using heavier bullets such as .270 Win. vs 6.5x55mm. Similarly, the reason the 7mm Rem. Mag. overan the .264 WM in popularity was because of the bullet, but it's important to note that it was a heavier bullet that made the slightly larger caliber more desirable, and part of that was due to what could be stabilized with old-school 1 in 12 twist rates. Comparing 6.5 Grendel and 6.8 SPC, the 6.8 does not enjoy any appreciable advantage in bullet weights. You're just not going to get the popular .270 bullets in there. What you will get is no heavier than what the Grendel will shoot very well with typical 1 in 8 twist rates. The 6.5mm will also shoot those same weights with a superior B.C.

In my opinion, the 6.8 could be more effective in terminal effects than the Grendel, but only in a case that is larger than the SPC. In an AR15 size, that would mean lower capacity like a .243 WSSM. Beyond AR15 length, it would mean an AR10 or a bolt-gun.

Another factor that isn't important to me, but quite obviously does matter to adopters that are concerned with political and commercial ramifications: the Grendel is based on the .220 Russian, which was based on the 7.62x39 and it was developed by somebody-Alexander. The 6.8 SPC is based on the red-white-and-blue .30 Remington, by Remington which has been all-American going back almost as far as the war of 1812 (and is actually Cerberus Capital Management).
 
Not without explaining your reasons for why. If you are going to take a side so emphatically, produce your evidence.
Grendel= ability at moderate to longer ranges.
Grendel= more factory ammo available.
Grendel= wider range of bullet weight for reloaders.
Grendel= more availability of current AR or Bolt platforms & parts.
In the context of this OP if you restrict this conversation to deer, say within 200 yards or so, no difference. But that doesn't make my statement any less true. Bill Alexander developed a cartridge that sent the 6.8spc team home from a set of trials back over a decade ago. In addition, aside from some out of production Remington Sevens, how many commercial bolt guns in 6.8 are being sold to deer hunters now?
 
I don’t have any insight, but I am currently making this decision myself. Started on the 6.8 side, but now I’m leaning 6.5. My build would primarily be for punching paper. The above information has been helpful.
 
Grendel= wider range of bullet weight for reloaders.

6.8 has useable bullets from 80 - 140 although anything above 120 is typically for subsonic loadings.

6.5 has useable bullets from 90 - 130 typically

So no difference if not a slight edge to 6.8

I will say the bolt action part is definitely a plus, but is a small niche as really both of these platforms are about what’s the best performance in an AR15, if one steps out into a bolt action they are bypassing .243Win, 7mm08, and many other more common rounds which will all leave both the 6.5 and 6.8 in he dust. But a current advantage no doubt for the 6.5, if one wants to match a bolt to their AR15. Now I say this as one who is going to buy or put together a 6.8 SPC II bolt gun as it will be an excellent starter gun for my kids when they get older.

However, if one wants a 6.8 bolt gun it’s just a barrel away on a 224 Valkyrie bolt gun, and who knows as if/when the 224 Valkyrie really takes off, its not too hard for a bolt gun manufacturer to spin on a different barrel in 6.8 SPC II (which are already rumored to be doing) and expand their product line into an already established cartridge. Currently, there are about 2-3 major manufacturers who have 224 Valkyrie bolt guns, and 2-3 higher end manufacturers.

Like I've said before these two are so close in performance, its really about the minutiae that one makes their decision. I happen to think the 6.8 SPC II wins out, others feel the 6.5 Grendel is better. But it's good for those making the decisions to have the information to decide.
 
Last edited:
I don’t have any insight, but I am currently making this decision myself. Started on the 6.8 side, but now I’m leaning 6.5. My build would primarily be for punching paper. The above information has been helpful.

If your primarily punching paper they both will do this well, however the 6.5 will do it better ballistically at 500 yards and further; once/if the 224 Valkyrie gets it's reamers and freebore worked out it will punch paper and do distance better than both.
 
Last edited:
I posted this on another forum.
After consulting with various reloading manuals I've found that the one limitation to the 6.8 SPC is bullet weight. Max recommended is 115grainers although Hornady makes a 120gr. bullet with a short ogive that will work.
As I understand it LMT makes a rifle dedicated to the 6.8 but requires it's own magazines that are wider to except longer cartridges.
SPC shoots 115gr. bullets to 2600fps. While the Grendel shoots 123gr. to around 2400fps. Think I'm better off with a 150gr. 30/30. View attachment 825722
My Howa Mini spits out 130 grain bullets from my 6.5 Grendel at 2450 with incredible accuracy. The downrange velocity and energy of that bullet will easily overtake a 30/30 at 100 yards, and my beloved 30/30 is no match for the little Grendel at longer ranges.
 
I found a used upper in 6.8. There’s a lot in that round that makes me love it but it’s trivial even by my own admission, and mainly based on its history. If I were buying now and had to choose, I would pick 6.8 again because I like .277 bore and already stock reloading components, but if it were not for my .270 in the safe I would be looking at 6.5 Creedmore and Grendel pretty heavily.
 
I put this together a few years ago. Add bullet weight to the 6.8 and you gain a little BC and lose commensurate speed, so they only get tighter together downrange. Add barrel length to the Grendel and you pick up some speed, making up for some early energy lag... nothing to get excited about. Want to see something interesting, throw the 6.5 Creed and 308win on top of this - there’s a difference between those two. No appreciable difference between these two.

35631725082_a010d06ae8_z.jpg
 
I would say look at the mags, bullets, and barrels available for both and pick whichever one has the component selection that looks better to you since I don’t see anything to really separate them beyond that.
 
I put this together a few years ago. Add bullet weight to the 6.8 and you gain a little BC and lose commensurate speed, so they only get tighter together downrange. Add barrel length to the Grendel and you pick up some speed, making up for some early energy lag... nothing to get excited about. Want to see something interesting, throw the 6.5 Creed and 308win on top of this - there’s a difference between those two. No appreciable difference between these two.

View attachment 825918
Not sure what bullet you plugged in to get your chart, but all the 110-115gr 6.8 loads I plugged in dropped from supersonic around 800 yards, there are 1/2 dozen 6.5 loads that are supersonic to 1k and there's almost 10' difference in drop between the 115 nosler 6.8 load and the 123gr Hornady black 6.5 in favor of the 6.5
 
Like has been said countless times, not much difference, I picked the one that makes the most sense on design strength, and in my mind the 6.8 SPC II won out. I'll take the 5moa of more drop at 1,000 yards for stronger bolt, magazine feeding, larger entrance wound and larger combustion chamber behind the bigger bore size to get the bullet moving quicker.

But with all that said, I could argue the merits of less drop and wind deflection on the 6.5 Grendel. They are both top tier AR15 cartridges, one cannot go wrong with either. And once someone develops a metal magazine for the LWRC or Sulzer arms 6.8 SPC lower than everyone will be talking about 130-140gr Bergers in the 6.5 Grendel vs. 6.8 SPC II discussions for long range shooting, and the results will be the same.

I assumed 20" barrels on both and it seems that the Grendel with the 123gr SST fell between 2,500-2,550 fps, whereas there have been plenty that have loaded a 20" 6.8 SPC II to 2,600-2,650 (and beyond) on the 120 SST. The biggest problem is it takes handloads for the 6.8 SPC II to meet it's potential because it's hamstrung (thank you Remington) by neutered commercial loadings now that SSA sold out to Nosler.

6.8 SPC II - Hornady 120gr SST, .400 BC, 2,650 fps muzzle velocity
6.8%20SPC%20II%20-%20Hornady%20120gr%20%40%202%2C650%20MV.jpg

6.5 Grendel, 123gr SST, .510 BC 2,550 fps muzzle velocity
6.5%20Grendel%2C%20123gr%20SST%2C%202%2C550fps%20MV.jpg
 
Last edited:
Neither me nor my son hunts with the .6.8 , but his godfather and my best friend does. He has shot deer, big ones to 320 yards with it and they didn't go far. He went 6.8 as soon as it was rumored the Army was fooling with it in Stan. Unfortunately no surplus over runs but the Hornady SST 120 grain load he hunts with is very accurate and devastating out to at least 300 yards on deer. I convinced him to NOT use it on Elk.
 
Palmetto would sometimes come into some Federal 90gr Bonded SP (XM68GD) from government overruns that was cheap. I haven't seen it in a year or so, but it was a very good price, I think around $0.36-0.40/round shipped.
 
Hopefully @brutus51 lets us know what he decides either way. And either way I'm sure he will be happy with his choice as they are both really efficient cartridges for the AR15 platform.
 
Not sure what bullet you plugged in to get your chart, but all the 110-115gr 6.8 loads I plugged in dropped from supersonic around 800 yards, there are 1/2 dozen 6.5 loads that are supersonic to 1k and there's almost 10' difference in drop between the 115 nosler 6.8 load and the 123gr Hornady black 6.5 in favor of the 6.5

I don’t recall exactly what bullet I used, but I can say I think you picked a very modest 6.8 load, or you’re comparing a 16” SPC load to a 24” Grendel - or maybe some old SPC Spec I data. Been loading and shooting these rounds for over 15yrs, not just looking up numbers online.
 
No disrespect to anybody here, but these little anecdotal opinions on killing ability based on personal experience in substantiating one caliber over the other are pretty darned pointless. Heck, there's a guy that kills huge feral boars on YouTube with a .22 subsonic. He claims 400 lbs for his big one. I don't know that it is that big, but it is certainly a substantial hog. It didn't complain about him using a .22 subsonic, either. I know guys who kill hundreds of hogs with their 6.8s. I know guys who kill hundreds of hogs with their 6.5 Grendels (me, included). That the calibers kill is more a testament to the shooter and his/her ability to utilize the weapon than the superiority of one caliber over the other. Sometimes this is due to superior marksmanship and sometimes it is because they can pull the trigger a whole bunch. Everybody looks amazing in trophy pictures.

They are both reasonable calibers for most hunters at typical hunting distances, which for the vast majority of hunters are inside 100 yards for most of their shots most of the time. I know plenty of guys that shoot farther than that, but when you get down to looking at shot distances for your typical hunter, they ain't shooting mountain peak to mountain peak. A survey done on Texas hunting forum several years ago had most hunters (96%) typically hunting inside of 100 yards, 98% inside of 200 yards. There were a few folks who preferred longer range hunting and that is to be expected. The point is, unless you are one of these specialty hunters, chances are you aren't making a whole lot of shots beyond 200 yards.

I spend a lot of time looking at terminal ballistics actually inside of killed hogs. I like to do the necropsy to see how bullets actually perform. There isn't anybody anywhere that is going to be able to tell the difference between the 6.8 SPC and 6.5 Grendel with comparable bullets. You can often tell differences in bullet type performance, but not between the two calibers. 6.8 typically has a bit more energy at shorter ranges which aids penetration potential, but Grendel bullets have a higher sectional density that aids penetration potential. So it is really a wash. Both will often overpenetrate hogs up to 200 lbs with broadside, boiler room shots that don't strike the humerus or spine, such as when using Hornady SST factory ammo (120 gr. for 6.8 and 123 for Grendel). You hit heavy bone going through the thick part of the animal and all bets are off on whether it will overpenetrate on a bigger hog or not.

If you reload, Grendel has more bullet options because of the numerous calibers that are 6.5. If you don't reload, buying online is your best way to find ammo at good prices. 6.8 has a LOT more commercially reloaded ammo available and you are more likely to find it locally or find more variety locally. Don't buy a Type I Grendel. They are the basis for the bolt breakage issue. Type II does fine. You will find more commercially available 6.8 rifles than Grendel rifles. Grendel folk tend to be builders

I spend time on both the 6.8 and Grendel forums and read the banter. Each side cherry picks little aspects of each caliber to make it stand out against the other and proclaim cherry picked failings of the opposing caliber. It is fine to be a fan, but a lot of this fanboy garbage is angels on the heads of pins held by tiny angels on the heads of tinier pins.

I really like my Grendels, but have never considered my shooting partners 6.8s to be in any way superior or inferior to what I am shooting when we go out to deal with the masses of Texas hogs. While there are some differences between the two, in the grand scheme when you are out in a field on a sounder of hogs, none of them seem to make a hill of beans difference.
 
Last edited:
Not that it would be my first choice, but after seeing what a 130 grain Sierra Gamechanger can do out of my Howa 6.5 Grendel, if I had to use it for elk, I would, provided the shot was under 200 yards. Next time I travel to Colorado to hunt with my son, it will be going as a backup rifle for one of us, if the need arises.
 
Look at the shoulder angle difference. 30° (Grendel) vs 23° (6.8). That should be all you need to know if you want to use the cartridge in an AR.

23° is the same as 5.56 x 45 and there's a real good reason for that.
 
I don’t recall exactly what bullet I used, but I can say I think you picked a very modest 6.8 load, or you’re comparing a 16” SPC load to a 24” Grendel - or maybe some old SPC Spec I data. Been loading and shooting these rounds for over 15yrs, not just looking up numbers online.
I was using loads listed in my Streloc pro app, I don't have a dog in the fight. It sure seems that 6.8 guys are into coolaid.
What I do have is a very good understanding of long range shooting and what it takes to do it constantly.
To get a .400 BC bullet to 1k it's gonna need to start above 2850 fps at 1320 ft elevation in today's air.
 
I want to thank all you folks for your input, this has been a very interesting topic. I've been scouring a bunch of forums trying to get educated on AR's in general. Since I just bought this new one I think I've become a little carried away with it. After researching reloading manuals, and reading all the opinions of different folks the one thing that really struck a chord with me was this fellow who posted an inquiry about sub-zero cold weather performance and lubricants required to keep an AR running. This really turned on a light bulb as just about all my 50 years of hunting has been in Michigan's U.P. I've hunted in 20 below weather with bolt action or lever rifles and never had a problem.
On one occasion I remember sitting in a Duck blind with temperatures in the low single digits. One fellow in our group had a really high end
semi-auto shotgun, think it was a Benelli, When the ducks came in his shotgun cycled so slowly it was pretty much a single shot. Really appreciated my old Remington pump that day.:D
Anyway considering a 6.8 SPC upper would cost 1K I could get a bolt gun in 6.5 Creedmoor for about the same money and be able to get better performance in addition to feeding my reloading addiction. Part of the deal is that in my old age my 30/06 is starting to hammer my shoulder.
Sigh getting old sucks.:(
 
Status
Not open for further replies.
Back
Top