A few 6.5 Grendel questions

[Fat Russian]

I am thinking about building an AR15 in 6.5 Grendel. What are the advantages and disadvantages of this round? How does it compare to the .308 at long range? What is the "best" barrel length, is 16" enough? I have several AR's in 5.56 and one in 6.8 SPC allready, should I go with a 6.5 or just move ap to a .308? And here is my dumb question, will the 6.5 round work with the 6.8SPC magazine, has anybody tried this? They appear to have the same mag body, I ask becuase I have one 6.8 magazine with a 556 follower (it came that way from C-Products) and it works fine for the 6.8 round. Sorry for the rambling post, and and all answers are appriciated.

FR

[tony549]

You'll find a lot of info on the 6.5 Grendel at this website. The round is ballistically efficient, but sources of ammo are fewer in number. Another very similar round is the 264 LBC which will chamber in the Grendel. The 123 gr bullet will stay supersonic past 1000 yds. Brass is expensive, but reloaders can fireform brass from 7.62x39. I thought about getting a 6.5 Grendel but decided to stick with 5.56x45. The last thing I need is another cartridge to support; another die set, brass, bullets and loaded ammo ($$$$).

[fastpat]

I am thinking about building an AR15 in 6.5 Grendel. What are the advantages and disadvantages of this round? How does it compare to the .308 at long range? What is the "best" barrel length, is 16" enough? I have several AR's in 5.56 and one in 6.8 SPC allready, should I go with a 6.5 or just move ap to a .308? And here is my dumb question, will the 6.5 round work with the 6.8SPC magazine, has anybody tried this? They appear to have the same mag body, I ask becuase I have one 6.8 magazine with a 556 follower (it came that way from C-Products) and it works fine for the 6.8 round. Sorry for the rambling post, and and all answers are appriciated.

FRI have several rifles in 7.62NATO, great rifles all of them. I'd used the AR-15/M16 for a very long time in the military, a very efficient rifles with an under-performing cartridge in my opinion. The 6.5 Grendel solved that issue for me. It's great having an under 8 pound carbine length rifle with the kind of punch offered by the 6.5G, I've had mine for 6 months now and have no regrets at all, except finding time to shoot it more, and finding time to load up the brass I bought for it.

I do not think the magazines for the 6.8SPC will function well using 6.5G ammo. The magazine follower is different and the feed lips are designed for the larger diameter case. Magazines are relatively low cost at $10.50 each, there's an alleged second magazine supplier in the wings, but as of today, it's vapor-ware.

[dp0350]

It seems that the 6.8 SPC is picking up steam quicker than the 6.5.

[Fat Russian]

Thanks for the replies, I have decided to go with a 6.5G when I am able and after a few other AR projects are completed. I have found the 6.8 SPC to be more readily available locally and recently came across some for less than a dollar a round, woohoooooo plinking rounds!!! I do agree that the 6.8 seems to be gaining wider acceptance, but I think that the Grendel is following along very well. Hopefully by the time I get around to building a grendel ammo will be more available.

FR

[Entropy]

It seems that the 6.8 SPC is picking up steam quicker than the 6.5.

I read a recent post by Dr. Roberts claiming that the 6.8 is being looked at again by the USMC. I haven't read anything to indicate any consideration of the Grendel. It's amazing how finicky the US military is when it comes to adopting new equipment. They try stuff out, say they like it, get the paperwork ready to make it happen, then back out at the last minute with little explaination.

[500grains]

I am thinking about building an AR15 in 6.5 Grendel. What are the advantages and disadvantages of this round? How does it compare to the .308 at long range? What is the "best" barrel length, is 16" enough? I have several AR's in 5.56 and one in 6.8 SPC allready, should I go with a 6.5 or just move ap to a .308? And here is my dumb question, will the 6.5 round work with the 6.8SPC magazine, has anybody tried this? They appear to have the same mag body, I ask becuase I have one 6.8 magazine with a 556 follower (it came that way from C-Products) and it works fine for the 6.8 round. Sorry for the rambling post, and and all answers are appriciated.

FR

I hope I can help just a little bit.

The 6.5 G is optimized for 120 gr bullets. However, the optimal bullet weight in 6.5 mm is 140 or 142 grains. As a consequence, the 6.5 G is not a true long range cartridge. If there were a 6.5 cartridge that fit into an AR15 which pushed a 142 grain SMK at 2700 fps with a 20 inch barrel that would be an excellent long range cartridge, good for deer out to 600 yards or bad dudes beyond that. I am imagining a 7.62x39 blown out to nearly straight wall, with an Ackley improved shoulder, and necked down to 6.5 mm, loaded with those new special powders that Hornady is using to get really high velocities out of normal cartridges like the .308 and 30-06.

The 6.8 SPC is really a 300 yard round and then due to low ballistic coefficient, it drops off. The 6.5 G gets you another 75 yards or so, but still does not stretch things that far. If you want longer range, get a 7.62x51, a 6.5 Creedmoor or a 260 Rem. on an AR10.

[DocGKR]

I fully concur with what 500grains has written above.

Like 5.56 mm and 7.62x39mm, the 6.5G and 6.8 mm are both assault rifle cartridges. The advantage of 6.8 mm is that it was optimized for 12-16" barrels and remains viable even down to 8" barrels.

If you want 500+ performance, you need a cartridge with more case capacity--something like 6.5 Creedmoor, 260 Rem, 7 mm-08, or 7.62x51mm (especially with 155gr Scenars or 175 gr SMK's). Unfortunately, these all require going up to a larger rifle than an AR15.

Fortunately, the new 16" barrel SR25EM, LaRue OBR, and LMT all are great choices.

[Fat Russian]

Thanks again for the input guys, I am always considering my options until I commit. I already have an AR chambered in 6.8 SPC and understand it's limitations beyond 300 yds. At this point I am really on the fence about the 308, I have had many 308's (M1A's and FAL's) over the last 20 years and never felt they performed to my desires, i am considering 308 AR platform down the road, I think mainly it is based on availability when I have the money. But then I guess my question is then going to be, what kind of performance can I expect from a 308 out of a 16" barrel versus a 20-24" barrel?

[Bill Alexander]

Funny! the Grendel is essentially a 7.62x39 with the shoulders blown out a 30 deg shoulder and is loaded with high energy flash suppressed ball powders, I believe Hornady uses one of those powders mentioned.

The current configuration will launch a 123 grain projectile with a Bc of 0.510 to 0.547 at a nominal 2520 fps from a 20" barrel. With this combination making a connection at 600 yards in blustery testing conditions is relatively easy and although not optimum for 1000 yards, shots onto LaRue targets are very doable. At these ranges they will roll the LaRue with authority.

We have run 14.5 inch barrels out to 900 yards and 10.5 inch barrels out to 500 yards. With good ammunition they provide excellent down range energy and shoot well through the wind. While I will concur that the cartridge will not match a 6.5x47 in its ability to get to range, stating that its range is 375 yards at best is laughable, 5.56 will get to this range with ease.

I have been exploring the performance of the new 12.75" barrels recently. Ongoing it seems that there is a requirement for more range ability but that the customer does not necessarily want to revert to a full size rifle. Most testing is at 600 yards, where it is possible to easily engage head size targets. Ability to penetrate the current level of vest and helmet with a ball ammunition is a given and an ability against plates with a specialized projectile is also present. While I would not ethically engage game at these distances from my own ability, what we have seen from the trials indicates that sufficient potential exists even from this abbreviated barrel.

Bill Alexander

[DocGKR]

Bill,

Thanks for the additional information. 12" barrels work well for many applications. Are you going to be releasing any terminal performance data on the short barrel 6.5G loads?

[fastpat]

I hope I can help just a little bit.

The 6.5 G is optimized for 120 gr bullets. However, the optimal bullet weight in 6.5 mm is 140 or 142 grains. As a consequence, the 6.5 G is not a true long range cartridge.A quick search of a few ammo producers reveals that Remington loads its 120 grain corelokt bullet in their 6.5 Remington Magnum, both 120 grain and 140 grain bullets in 260 Remington. Nosler only produces a 120 grain bullet in their Ballistic tip for all 6.5 bore cartridges and so on. Based on that and current experience for most folks, most 6.5mm/.264 cartridges are at their best with 120-130 grain projectiles. The 6.5 Grendel appears to work best with 123 grain bullets.
If there were a 6.5 cartridge that fit into an AR15 which pushed a 142 grain SMK at 2700 fps with a 20 inch barrel that would be an excellent long range cartridge, good for deer out to 600 yards or bad dudes beyond that. I am imagining a 7.62x39 blown out to nearly straight wall, with an Ackley improved shoulder, and necked down to 6.5 mm, loaded with those new special powders that Hornady is using to get really high velocities out of normal cartridges like the .308 and 30-06.

The 6.8 SPC is really a 300 yard round and then due to low ballistic coefficient, it drops off. The 6.5 G gets you another 75 yards or so, but still does not stretch things that far. If you want longer range, get a 7.62x51, a 6.5 Creedmoor or a 260 Rem. on an AR10.The 260 Remington is a really fine cartridge, available in a large number of bolt action rifles and in AR10 sized rifles and in FAL's.

However, for a lightweight, handy rifle, with superior ballistic performance, it's hard to go wrong with an AR-15 chambered for 6.5 Grendel.

[500grains]

So I was looking at the 30 Rem AR case dimensions and it is a bit larger than the 6.5 Grendel. I wonder if it has enough case capacity to push the 142 gr SMK to 2600 fps if it were necked down to 6.5 caliber.

[Entropy]

Bill,

Are you going to be releasing any terminal performance data on the short barrel 6.5G loads?

+1

I could care less how much muzzle energy is retained at 1000m. If the bullet just zips through the target, or has a delayed upset in tissue it isn't all that impressive. How about a peak upset of around 4" of penetration? Can we see some proper FBI protocol(correct gel calibration) testing on the Grendel? The only testing I've seen is with the dyed gel blocks performed by that Speer ammunition distributer by methods unknown.

[fastpat]

+1

I could care less how much muzzle energy is retained at 1000m. If the bullet just zips through the target, or has a delayed upset in tissue it isn't all that impressive. How about a peak upset of around 4" of penetration? Can we see some proper FBI protocol(correct gel calibration) testing on the Grendel? The only testing I've seen is with the dyed gel blocks performed by that Speer ammunition distributer by methods unknown.You mean tests like these (http://www.65grendel.com/art004balltests1.htm)?

Info like this (http://www.65grendel.com/faq.htm)?

The tests from 2006 are referenced here (http://www.worldlingo.com/ma/enwiki/en/6.5_mm_Grendel) as well.

[Entropy]

You mean tests like these (http://www.65grendel.com/art004balltests1.htm)?

Info like this (http://www.65grendel.com/faq.htm)?

The tests from 2006 are referenced here (http://www.worldlingo.com/ma/enwiki/en/6.5_mm_Grendel) as well.

Where are the pictures? Calibration BB marks? Names of the testers? How about the testing facility? Grendalizer was given all this detailed performance data, yet he was not allowed to show any evidence that the tests actually occured? I find it very difficult to believe that Grendalizer was allowed to make public the testing data, but he was not allowed to post pictures of gel blocks or indicate who hosted the testing event and who were the experienced testers who performed the testing.

During the 2006 green dye test, Grendalizer said that the test was performed by CCI Speer. Dr. Roberts confirmed that it was actually performed by a Speer ammunition distributor(ammo salesman), and that the tests did not appear to be according to FBI protocols.

The data I have seen from the Grendel fan website does not convince me that it is authentic. One of the few Grendel gel tests that I trust would be on page 15 of this presentation:
http://www.dtic.mil/ndia/2008Intl/Roberts.pdf

It doesn't seem to be that impressive compared to a similar 6.8 loading through a windshield. You can even see the calibration BB on most of the gel blocks.