6.5 grendel or 6.8 spc?

[Cornbread]

Well you ask that question here what answer do you think you will get? Go ask that same question on the 6.8 forum and see what those folks have to say. I happen to own both and have shot and reloaded for both. I'm not a koolaid drinker of either round. So here's my unbiased two cents. If you told me you were going to be hunting inside 200 yds like most hunters and did not reload I'd say go 6.8. When I wanted to build an Ar for my grandson to hunt with I built a 6.8. My son doesn't have time to reload. I don't consider ammo you have to buy on the net from second tier manufacturers "factory" ammo. My local Cabelas carries 120 sst, 115 federal fusion, 100 Hornady GMX and Federal 90 gr gmd. The only hunting 6.5 load is the 123 sst. My 16" ARP equals my 18" 6.5 in factory ammo velocity and reloads. Now you said you do reload and you want to target shoot. Then the grendel is the way to go. Lapua brass and higher bc bullets makes a big difference at longer ranges hunting and target shooting. I would go 18-20" minimum barrel length.

[stanc]

What are you trying to accomplish with your build, if this is a serious first post?

There isn't a single application that the 6.8 SPC will do better than the 6.5 Grendel, whether we're looking at:

Hunting
Target
Military

Can you get an ultra-compact, 8" barrel, 6.5 Grendel SBR with 30-rd magazine?





Or a belt-fed, 6.5 Grendel LMG?

https://www.youtube.com/watch?v=z2Pq4_XdA-k

[LRRPF52]

Well you ask that question here what answer do you think you will get? Go ask that same question on the 6.8 forum and see what those folks have to say. I happen to own both and have shot and reloaded for both. I'm not a koolaid drinker of either round. So here's my unbiased two cents. If you told me you were going to be hunting inside 200 yds like most hunters and did not reload I'd say go 6.8. When I wanted to build an Ar for my grandson to hunt with I built a 6.8. My son doesn't have time to reload. I don't consider ammo you have to buy on the net from second tier manufacturers "factory" ammo. My local Cabelas carries 120 sst, 115 federal fusion, 100 Hornady GMX and Federal 90 gr gmd. The only hunting 6.5 load is the 123 sst. My 16" ARP equals my 18" 6.5 in factory ammo velocity and reloads. Now you said you do reload and you want to target shoot. Then the grendel is the way to go. Lapua brass and higher bc bullets makes a big difference at longer ranges hunting and target shooting. I would go 18-20" minimum barrel length.

I heard this for years and years, and kinda just took people's word at face value until I saw what a 16" Grendel actually does mv-wise. The reality is the 6.8 has no performance advantage within 200yds for hunting, even when compared against the tweaked chambers in 6.8 designed to produce more velocity. Anyone can see this for themselves if they do an analysis between the 2:

6.8 mod chamber, 16" barrel, 120gr SST, 2481fps, BC = .400 G1 This was actually a hand load I found, not Hornady's stated 2460fps, but the difference is negligible.

75yds 2322fps 1472 ft-lbs
100yds 2270fps 1408 ft-lbs
150yds 2169fps 1285 ft-lbs
200yds 2070fps 1170 ft-lbs

6.5 Grendel, 16" barrel, 123gr SST, 2450fps, BC = .490 (not using Hornady's Doppler-tested BC, using a reduced BC just to placate the counter-argument)

75yds 2321fps 1471 ft-lbs
100yds 2278fps 1418 ft-lbs
150yds 2195fps 1316 ft-lbs
200yds 2114fps 1220 ft-lbs

There are provably zero performance advantages to the 6.8 within 200yds for hunting applications. There is more deflection, less energy, less impact speed, using the same bullet from the same manufacturer. Both will expand within that range to at least .50 caliber, but the 123gr SST will have more tail end behind the mushroom to drive penetration through the animal.

I can then take that same SST load and shoot it as a target load out to ranges that most people don't even have access to, but the capability is there. There is no need to buy a separate target load, a premium solid, etc. If one load from Hornady can do more than all of the 6.8 loads combined, why would I want the one with less performance, and premium bullets that can't do what the affordable 123gr SST can do? One zero, done.

Then, to illustrate the point further, take a 14.5" Grendel with factory 123gr SST against the hand-loaded 16" 6.8 SPC.

14.5" Grendel, 123gr SST, 2420fps

150yds 2167fps 1283 ft-lbs
200yds 2086fps 1189 ft-lbs

If you want 16" 6.8 hand-loaded performance at 150yds, the 14.5" Grendel with factory ammo will do it, and then slowly out-perform it from then on, with less wind drift as well, less chamber pressure, with one load that does what no other 6.8 load can do.

[Cornbread]

All I can do is relate my own experience with both rounds as a non koolaid drinker who has no stake in the success of either.



This is a chrono reading from factory 123 sst with an 18" barrel. The highest reading was 2425. The chrono as always was verifed with some .22 of known velocity. Factory 6.8 120 sst runs about 2450 from my 16". If you subtract 25 fps per inch you get pretty close to what Hornady lists for the 16". The 6.8 has a higher saami max pressure.With an almost identical case capacity it makes sense that the 6.8 will be slightly faster. Truthfully the two are so close it's a tossup. For the hunter non reloader I allways recommend 6.8 as there are more locally available choices in ammo. For the reloader, target shooter the lapua brass is a huge plus to go with the higher BC bullets. I do wish that Nosler would make an accubond specific to the 6.5 like they do with the 100 gr 6.8. I'm not a great fan of the sst in any caliber.

[Cornbread]

I just checked my data book. For the 123 amax, sst with 28 gr 8208 the average velocity for 30 shots was 2482. Looking at the data on this site and the Grendel load book that is pretty much inline with the data I'm seeing. My 16" arp with a 120 sst and 27.5 gr 2200 averaged 2480 fps for all my data. With 100 gr 6.8 bullets I can get right at 2700 fps with 2200 in the 6.8. I have yet to get a 6.5 100gr to 2700 fps . Looking at the Grendel load book data for 16-18" barrels I think that is in line too.

[LRRPF52]

2414fps is pretty slow for an 18" Grendel, but within the 100fps variance you can see in barrel-to-barrel. I've chronographed a lot of 18" barrels, and have never seen that low of a speed with 123gr SST.

What was your 5 or 10-shot average when you chronographed that load, and what temperature was it outside? If it was just one sample, the rest of the loads could have been much higher, and you see that with factory ammunition.

Hornady's data for the 16" is not a 16" either. It's a really slow 14.5" at 2350fps, with a pinned muzzle device. I called their tech department and confirmed it, although I already knew it because I know both the sender and receiver of the test gun for that. Since it's pinned for legality, it technically is a 16" barrel, but not really.

From my 17.6" Lilja, 123gr SST factory:

2441
2467
2477
2489
2481

Avg: 2471fps

From another 18" Lilja,
2468
2441
2421
2495
2453

Avg: 2455fps

And a 2414fps 6.5mm 123gr SST still exceeds the performance of a 2480fps 6.8 120gr SST at 200yds. It matches it at 150yds. Where the 6.8 has a slightly higher working pressure, the Grendel has a much more efficient powder column and case design for combustion. Combine that with a substantially higher BC, and it all starts to make sense why the Grendel exceeds the 6.8 within 200yds for a hunting cartridge. Terminal performance is another story, where again, both will expand with the same bullet type, but the longer 6.5 has more tail end to drive it through.

They are so close to each other within 200yds in exterior ballistics, that is true, although the Grendel really does out-gas it slightly from the muzzle, with less drift, more impact speed on target, way better sectional density, which translates into penetration.

Different areas of the Nation have different availability. I know Cabella's has had both for years now. Sportsman's has both. I personally can't justify spending shelf prices when I can get ammo for so much less online, and I recommend getting ammo online for that reason.

I got the 100gr Nosler Ballistic Tip to 2700fps with 8208 within the 1st year of loading for 6.5 Grendel, without even hitting Hodgdon's max load of 30.8C, which was 47,600psi when they tested it in their Piezoelectric system. But again, I looked at the numbers at realistic hunting distances, and quickly saw that the slower mv 123gr out-performed the 100gr NBT, so I never messed with it again.

Mv is not where it is at. On-target impact speed is what I look at. I think that's the biggest obstacle a lot of people are still hung up on, and I was for years as well, especially being raised on .270 with a 130gr going over 3000fps at the muzzle.

[Cornbread]

It was 75 degrees. Over ten shots on the chrono the range was 2414-2425. Your 18" gets 2455 which is about what I get with the 120 sst in my 16" 6.8. Of course with the bc difference the 6.8 will bleed velocity more than the 6.5. Inside 250 yds the difference is not that great. Around here there is a bunch more 6.8 on the shelf. A bigger variety of hunting bullets also. The 123 sst is the only load you find for the 6.5 in lgs around here. This is the main reason I will recomend the 6.8 to the average joe who doesnt load his own and wants to shoot factory ammo. As a reloader and long range shooter I appreciate the higher bc and of course the Lapua brass for the 6.5. I really wish I had gone 20-22" with the barrel on mine. The 6.8 is really made for a 16" hunting rifle for shots inside 250 yds. The 6.5 benefits more from a longer barrel with those higher bc bullets. My next build will probably be a 22" 6.5 with a match grade barrel to stretch it out and take full advantage of what the round has to offer while still being more user friendly than an ar 10 platform.

[JASmith]

CB, I am unsure of where your logic is coming from beyond justifying a personal choice in calibers.

There is nothing wrong with one's choice. There are those who still swear by the 44-40 for deer hunting, even though they will need to use bow-hunting techniques to get close enough. Frankly, the wide variety of personal preferences is the source of the dynamics behind wildcatting and the introduction of new factory cartridges.

In truth, a deer or hog cannot tell the difference between the 6.8 or the 6.5 as long as the bullet hits on the same spot and both bullets are above their threshold expansion velocity.

The ease of attaining a proper hit is what separates the two cartridges beyond 250 yards.

Regarding barrel length, run the numbers for drift in a 10 mph wind for the 16, 18, 20, 22, and 24 inch barrels with the 123 gr SST. Do this for 300, 400' and 500 yards. Next, compare the difference in drift with the 3-moa field accuracy most of us actually see.

That 3-moa is there because ot is really difficult to dope wind, accurately, for example. Further, we rarely get target range equivalent support for the rifle in the field. These and other factors like excitement tend to degrade out accuracy in the field.

Bottom line, even a 24-inch barrel doesn't buy a lot compared to the 18-inch barrel. Some prefer the 16-inch Grendel because it is even more convenient to carry while getting the accuracy and punch needed to reliably harvest game out to well beyond 400 yards.

[Cornbread]

CB, I am unsure of where your logic is coming from beyond justifying a personal choice in calibers.

My advice to a casual shooter, hunter to get a 6.8 is based on the FACT that every time I go to Bass Pro,Cabelas or one of the 2 Academy stores around here there is a much greater selection and availability of factory ammo. In fact Bass Pro here is not carrying any 6.5 ammo. The only available hunting option is the sst. Cabelas and Academy will usually have the 100gr gmx, 115 fusion and the sst in 6.8. Cabelas will sometimes have the 90 gr GD also. Invariably these guys buy some ammo, sight in the rifle and then 2 days before opning weekend they realize they need another box of ammo. They are used to just buying their 270 or 3006 ammo off the shelf. Also,if a non reloader doesn't like the sst he is sol. Now if I know that a guy is a reloader and an avid shooter I will recomend the 6.5 because he can load what hunting bullet he wants and the lapua brass is top notch plus the higher BC bullet availability. I do wish that there were more bonded bullet options in 6.5. The partition is a good hunting bullet but I've never been able to get great groups with a partition in any caliber and the bc is not that great compared to other options.

[A5BLASTER]

Sorry cornbread, I don't buy that the spc is better then grendel simply because in your area thier are more ammo options on the shelf for the spc then grendel.

I personally don't see the fight between these two fine calibers as worth while to get into but I also can't agree with your stance to tell folks, if you don't hand load the grendel is not for you.

I don't hand load and I still choice the grendel as my hunting round over the spc because it allows me to have more accuracy at longer ranges then the spc.

It most only be your area that local shops don't sell grendel ammo because near me all acadamys stock it as well as bass pro and cabelas even the local mom and pop places are starting to stock it as well.

[LRRPF52]

If the SST will do what all the other 6.8 loads will, but better, and then is also a great target bullet, why would you recommend 6.8 for hunting? I read some reviews on that Federal 6.8 Fusion load, and half of the people had pigs that traveled 20yds after the shot. Cheapest price I can find online for it is $19.99, over a dollar more than 6.5mm 123gr SST.

You can also offer to provide ammo for people and do ammo buys together online, and save a ton.

The only time I have bought ammo from Cabella's is if I have a coupon, and that was years ago. Look at the hunting threads here for how the 123gr SST performs on game from short barrels.

[Cornbread]

I did not say the 6.8 was a better round than the 6.5. I simply said I would recommend it as a better fit to someone who did not reload and shot critters at close range. This is where I think the Grendel guys have such a hard time accepting reality. Yes the 6.5 has better ballistics than the 6.8 yet the 6.8 is more popular as evidenced by the ammo market which does not drink koolaid and only reflects market conditions. Sometimes you cannot explain why one round gains popularity. Take the 300 BO. In my mind it makes no sense as the supersonic ballistics sucks and it's expensive to shoot subs. Yet you cannot argue that is has become extremely popular. I personally believe that Alexander arms maintaining proprietary status of the grendel for so long actually hurt the round. In 2009 Hornady and alexander had an agreement but it was 2011 before it was officially released to saami. By then the 6.8 had gained a foot hold in the market.

[ahillock]

With advent of the Internet, who cares what is available locally. 6.5 Grendel >>>> 6.8 SPC and it isn't even close.

[stanc]

With advent of the Internet, who cares what is available locally.

If I were still able to shoot regularly, I would care. I prefer to walk in and pay cash.

[JASmith]

My advice to a casual shooter, hunter to get a 6.8 is based on the FACT that every time I go to Bass Pro,Cabelas or one of the 2 Academy stores around here there is a much greater selection and availability of factory ammo...

One way to get ammunition flowing into the local gun store is to special order some. The gun stores stock what sells. They will stock any legal item as soon as they see a market for it. The special order path is one way to get their attention.

Most of us have no quarrel with someone preferring a particular cartridge over others.

We DO have a problem with faulty or incomplete logic being used to help cement the status quo.