6.5 Grendel vs. 300 Blackout: Ballistics, Applications, Ammo, & More

6.5 Grendel vs. 300 Blackout: Ballistics, Applications, Ammo, & More
September 7, 2022 Edited March 28, 2023 6918 view(s)
6.5 Grendel vs. 300 Blackout: Ballistics, Applications, Ammo, & More

Which Will Work Best For Your Needs?

Nineteen Sixty-Four. What a great year! The Beatles appeared on the Ed Sullivan Show four days before my twelfth birthday, the “new-old” restoration project Ford Thunderbird sitting in my driveway that my sons bought me as a project car was built and sold, and the M-16 made its debut in the Army. Huh? That introduction opened the doors to what is today probably the best-selling sporting and tactical rifle going, the AR platform, the modern sporting rifle.

At last, we hit upon the topic of this article… comparing two popular AR-platform cartridges. They were designed to be used in an AR-platform rifle, using the same bolt head size (in the case of the Blackout, at least) and the same magazines. So, they are both common and popular these days as that type of rifle has grown by leaps and bounds in sales. Heck, I even killed a deer last November with my Bear Creek Arsenal 7.62x39 AR … that says a lot, for me as I usually favor handguns. But it worked admirably and did the job at 151 yards. So now, let’s look at a couple of more calibers that Bear Creek Arsenal chambers ARs in… the .300 Blackout (BLK), and the 6.5 Grendel.


First, Some Background On Each One

I always like to include a bit of background about whatever cartridge I’m writing about, and this time will be no exception. I like to read the backstory about development and history as I always have been a history buff since I’ve seen so much of it… At any rate, let’s take a quick look back.


.300 BLK

From its inception in 2009 and production the next year, the .300 AAC Blackout (to call it by its full name) was designed from the beginning by AAC to be compatible with ARs in .223/5.56 caliber with just a barrel change. The rifle used the same bolt face and magazine as the .223. Stick a different barrel on it and then have available all the advantages of an AR but in a higher-energy .30-caliber round.

Remington worked with AAC to bring out this new cartridge, as previous efforts to adapt the 7.62x39 to the AR platform weren’t successful. Why not? Well, mostly because the steep case angle of the “Russian Short .30” did not allow reliable feeding, and the case head was a different diameter. So, they came up with a brand-new round that worked right off the bat. As stated above, everything about the round and its rifle is the same as the .223 version except for the barrel and the case being necked up to .308 caliber.

Several militaries use the Blackout, including the U.S. Special Operations Command (they picked it up this year), the United Kingdom, and the Netherlands. Sportsmen have flocked to it, as it delivers 7.62x39-type ballistics in a reliable platform. I am a believer in these intermediate .30 calibers after taking that doe that I mentioned above. She went down at a measured 151 yards like a truck had hit her - as the Monkees so eloquently put it, I’m a believer! And, this was out of a very reliable AR rifle - Bear Creek figured out the feeding issues because it goes “bang” every time I want it to.

300 BLK Ammo on table


6.5 Grendel

The 6.5 Grendel was designed, from the beginning, to be as accurate at longer ranges as the .308 but without the recoil. The name comes from a mythical monster antagonist in the epic poem Beowulf - I found that interesting.

The Grendel trademark is owned by Bill Alexander (of Alexander Arms), one of the cartridge’s designers.

The Grendel is based on the .220 Russian case with its larger case head than a .223 case. The larger case head meant that the bolt face would have to be adapted, so a new bolt was required along with the replacement barrel.

The larger 6.5 Grendel fits 26, not 30 rounds, in standard STANAG magazines. For many people this is a non-issue, as they are happy with the 6.5mm “punch” provided.

Introduced in 2003 at the Blackwood Training Facility, it quickly outshot the .308 at distances of around 1200 yards, with less recoil. It stayed above 1200 f.p.s. at even longer ranges. The combination of a shorter, “fatter” case that allowed more powder volume with a high ballistic coefficient .264 caliber bullet was a good one. It allowed greater accuracy at longer ranges.

In terms of service, the 6.5 Grendel is being adopted by Serbia. I believe that the adoption process “legitimizes” a new cartridge and causes it to be viewed with even more acceptance among the shooting public, but the Grendel had “been there, done that” before Serbia picked it up. It just works.

6.5 Grendel Ammo on table



Let’s look at the ballistics between the two cartridges. I think we can safely make one generalization right up front: the Grendel will have 400 f.p.s. and 500 ft./lbs. of energy over the Blackout at the muzzle with the same size bullet. Of course, that comes with more than a doubling of recoil energy in foot/pounds… 8 for the Grendel, 3.3 for the Blackout. If recoil matters to you, there you go. These recoil numbers are pretty low anyway, but there is a difference.

Here’s a chart that shows the BLK and the Grendel’s trajectories, assuming a 100-yard zero:

300 blackout vs 6.5 grendel ballistics chart

As we can see from this chart from shooterscalculator.com , both cartridges are fairly even starting at their 100-yard zeros. If you discount the subsonic Blackout round and only look at its faster stablemate, we are pretty much tied until 300 yards when a difference starts to appear.

The Grendel’s faster up-front velocity puts it on a flatter trajectory than the Blackout at any normal hunting range. But… is this necessarily a bad thing? If we limit our use of the Blackout to shorter ranges (up to 150 yards or so), it can be deadly effective on hogs and deer. The Grendel just reaches out and touches things at a greater distance but if you know that upfront, you can make an informed decision.

Here is an interesting chart thatsums things up pretty well in terms of ballistics comparison between the two…


6.5 Grendel 123 gr vs .300 Blackout 125 gr Cartridge Comparison Table.





Bullet Velocity (Muzzle)

2,580 ft/s

2,175 ft/s


Bullet Velocity @ 100 yds

2,410 ft/s

1,932 ft/s


Bullet Velocity @ 200 yds

2,246 ft/s

1,708 ft/s


Bullet Velocity @ 300 yds

2,088 ft/s

1,505 ft/s


Bullet Energy (Muzzle)

1,818 ft-b

1,313 ft-lb


Bullet Energy @ 100 yds

1,585 ft-lb

1,036 ft-lb


Bullet Energy @ 200 yds

1,377 ft-lb

810 ft-lb


Bullet Energy @ 300 yds

1,191 ft-lb

609 ft-lb


Usage @ 0 yds

Large Game

Medium Game


Usage @ 100 yds

Large Game

Medium Game


Usage @ 200 yds

Medium Game

Small Game


Usage @ 300 yds

Medium Game

Small Game


Recoil Energy

7.9 ft-lbs

3.32 ft-lbs


Recoil Velocity

8 fps

4.95 fps


Recoil Score*




* Cartridge ballistics, usage, and recoil figures taken from Sportsman's Warehouse rifle ballistics and rifle recoil tables. Recoil score based on weighted average of recoil energy and recoil velocity normalized between 1 and 10.

As we examine this chart, we begin to see that the Blackout really can’t keep up with the Grendel at any past fairly short range in terms of velocity and energy. This translates into bullet expansion (or lack of expansion) – the Blackout will tend not to expand much past 150 yards or so, while the Grendel is usually good to around 400 yards. This would depend a lot upon the individual bullet, of course, but is a generality that we can at least consider when selecting our rifle.



OK… let’s see which of these cartridges is better for specific tasks. I’ll do a simple box checklist and then explain it below.


.300 BLK

6.5 Grendel



Long Range Shooting



All-Around Shooting

Alrighty. We would all most likely agree that either of these fine cartridges would suffice for any of the tasks listed, but let’s get academic and look at them in a little detail. Let’s see why I placed my check marks where I did.



First, what type of self-defense? Personal encounters? A band of roving goons a football field away? We’ll assume close encounters of the personal kind.

With its .30 caliber bullet, the BLK wins. It comes close to replicating the ballistics of the “Russian Short .30”, the 7.62x39, and nobody ever said about that cartridge that it could not do the job on the battlefield.

Another big plus is that if you are running subsonic ammo, a suppressor might be in order. The BLK is one of the very few cartridges that works well suppressed when used with the proper ammo. This could be a big deal in a defensive (or hunting, where legal) situation.

Why not the .264 Grendel? It would work, but it wouldn’t be ideal for close- to medium-range encounters as its velocity and energy (and penetration) work against it. For targets way out there, sure - go for it.


Long-Range Shooting

Here, the 6.5 Grendel wins. It has the ballistic coefficient that enables it to keep slick and not drop much to ranges out to 1000 yards. This has been proven. Some shooters call it an equivalent to the .308 at long range but with less recoil, and that’s how it was designed. The BLK’s steam has gone pretty much by 300 or 400 yards.



I checked both boxes because both are good at hunting – they just hunt at different ranges and different types of game. As the chart above shows, the BLK excels at close- to mid-range shots at smaller types of game, up to deer. It shines on hogs at 100 yards or closer.

As I said above, its ballistics are hard on the heels of the 7.62x39 and that round will take deer. You just have to get a bit closer. The Grendel shines at mid to longer ranges, for large game. If you were to look up (in my fictional AR Hunting Guide book) rifles fit to hunt some of the larger critters from mid- to longer- ranges, the Grendel would have its photo front and center along with a few others.


All-Around Shooting

Again, I checked both boxes. There are rifle shooters out there like me that are more interested in closer ranges, out to a couple of hundred yards – I guess that’s because of all the handgun hunting I’ve done, in and around my smaller Indiana stomping grounds. The BLK would be indicated for that use.

On the other hand, those of you who are in the wide open spaces who won’t even look at a target unless it’s 800 yards away might be better off with the Grendel. That’s what that round was designed for – targets and game at a good distance. The 6.5/.264 caliber just tends to lend itself to long-distance shooting.

So either one would work for all-purpose shooting but especially if your purpose leans towards targets either not too far away, or way out there.

6.5 Grendel vs 300 Blackout ammo


Other Considerations

Ammo Cost & Availability

You have to take into account the cost and availability of ammo before you buy a rifle unless you happen to own an ammo factory. I don’t have one among my holdings, so I am careful to check these two criteria before I plunk down any dollars on a rifle. Even though I reload, I still want factory ammo to be available.

My go-to online source for what I consider fair ammo prices is Lucky Gunner. I’ve had good results from them, plus you can usually see a gel test (of handgun ammo, at least) of what you’re considering buying. I discovered the following when I looked up both our cartridges…

(All pricing was good at the time of writing).

300 BLK

I will include a link to the .300 BLK page on Lucky Gunner, as individual load linking would be an onerous task. They show 39 different brands/loads, with all available bullet weights and styles. Per-bullet pricing ranges from $.98 to $2.50, depending again on bullet and brand.

6.5 Grendel

There was just one load listed, a Wolf (Russian) Military Classic 100-gr FMJ number at $21 for a box of 20.

All of the ammo listed for both calibers was in stock. As a control of sorts, I visited my local Academy Sports & Outdoors store’s website. They had 12 assorted 300 BLK and 6 different 6.5 Grendel loads in stock, hovering at between approximately $1.15 and $1.50 per round. I would assume that the more I searched, the more I might find that the ratios or proportions of the two calibers in terms of in-stock ammo might be the same… about twice as much of one as the other. There will be those readers out there who know of different situations (Ammoseek comes to mind). I truly get it, as this is not exactly a scientific inquiry into supplies of ammo but just a quick comparison to see which of the two calibers seems to be the most popular on dealers’ shelves.



Of the two calibers, if you want to run a “can” on your rifle, the .300 BLK would be your huckleberry. The 6.5 would work, but with subsonic ammo readily available for the BLK, there would be no reason to go with the other caliber. I could see using a suppressor in a home defense situation. Having to fire a rifle indoors would be very loud, and a suppressor would help with that. I have hearing loss, and it’s no fun… might as well save yours when you can. Even range shooting would be more fun if the rifle was quieter. A last thought – suppressed hunting would be just the ticket, where it’s legal. Speaking of legal, here are two places to start shopping for your suppressor: Silencer Central, and the Silencer Shop.



I did a quick search on Bear Creek Arsenal’s website and came up with the following numbers of rifles for sale in each caliber, some of which are right-side charging. This count is of complete rifles.

.300 BLK Rifles : 15 total.

6.5 Grendel Rifles : 31 total.

Please follow the links for each caliber to see specific rifles. Uppers alone are available, as well. I would assume that this ratio of BLK to Grendel might be fairly standard in the industry. It would seem that the “hotter” of the rods is made in greater numbers.



As we examine our two cartridges and their popularity, it might pop into a prospective buyer’s mind that the 6.5 Grendel would be the way to go. There is enough ammo out there to keep your Grendel running for a long while. And, if you are like me, you have reloading gear attached to a bench in your garage or shop… that helps ameliorate any difficulty in finding suitable (non-FMJ) hunting ammo.

One factor that does not change between the two rifles, however, is that they are both ARs and are subject to the huge world of accessories and add-ons for that rifle type. Whether you end up with a .300 BLK or a 6.5 Grendel is rather beside the point - you can customize either to your heart’s content. It’s really up to you which one you choose. They each do different things better but in the end, at least one of them would probably do what you want it to. If you own these calibers, let’s hear from you below!

[We'd like to extend a huge thanks to Mike Hardesty for his hard work on this article! For more information on guns, calibers, and more check out our other articles such as 6.5 Grendel vs. 6.5 Creedmoor and Guide to Coyote Hunting. Shop our high performance products below!]


Please login to comment.

Don't have an account?

Sign Up for free
Cory B
September 7, 2022
Nice article. That pretty well reinforces what I had already believed to be true and added more detail simultaneously. It was information like this that led me to my choices when I purchased the BCA 18" 6.5 Grendel side charge upper as well as my BCA 10½ 300blk side charge upper
LeeRen Ray
September 9, 2022
Very nicely written! Good info, and I agree with it all. It's not a surprise that when comparing any cartridge with another, it really comes down to preference and intended use. These two certainly shine in the areas for which they were designed. BCA sells uppers for both of these cartridges that I think are top quality.
September 10, 2022
Great article but you left out import information for both. If you reload, you can make 300 Blackout cases out of 5.56 cases found everywhere lying around at the range. You can also easily make 6.5 Grendel cases using 7.62x39 cases that again you can easily find at most ranges. I own rifles in both calibers that bear the "Bear Creek Arsenal" logos. They are awesome uppers and handle everything I feed them with zero issues. Accuracy is sub-moa to 1.5 moa with 5 shot groups at 100 yds.
Mike Hardesty
September 18, 2022
Jack, you're right. Being a reloader, you'd think I'd mention that! Thanks!
Paul Kopp
September 10, 2022
I've had a 300 BLK for many years. As an Eastern deer hunter the 300 does a great job where our shots rarely exceed 100 yds. I have taken both deer and hogs. I considered a 6.5 Grendel but over the past 2 years ammo has been non existent whereas 300 BLK has been adequate.
Timothy cochran
September 10, 2022
I have both uppers and I like them both I'm in commie fornia and grendel ammo is hard to find but that grendel shhot straight as a arrow my 300 is nice but I believe the barrel will need to be broken in before I can start getting a nice group booth were purchased from BCA and I love em you can't go wrong
September 11, 2022
The Thompson Power factor multiplies the cartridge ballistics and multiplies by caliber. This gives a benefit to the 300 which tends to even out the differences. Not much, but a benefit.(in this comparison)
Tomas Recinos
September 11, 2022
I have a 18 inch and 16 inch this caliber is perfect for younger hunters and ladies because the recoil is very mild and not intimidating at all i wish the ammo was a little more affordable but we work with what we have nice article by the way
Tomas Recinos
September 11, 2022
I have the 6.5 grendel in a 18 inch and 16 inch this caliber is perfect for younger hunters and ladies because the recoil is very mild and not intimidating at all i wish the ammo was a little more affordable but we work with what we have nice article by the way
James T
September 11, 2022
I have a BCA 8.5 300 Blackout, it is a very good shooting AR. Take the grandson's to the range with me sometimes, they love shooting it also, the oldest has already ask me to give it to him when he gets old enough or if i decide to get rid of it. I keep it between the nightstand and the bed with a light attached for that bump in the night,
February 12, 2023
Well, I solved my delima by this trick........My AR pistols:........ 8.5" 5.56 .......8.5" 300 BLK ........... BCA 10.5" 6.5 Grendel My AR rifle delima trick...... 16" 5.56 .......18" 300 BLK........ 18" .223 Wylde Match ....... BCA 20" 6.5 Grendel ....16" 458 SOCOM I know...I"m hooked.
December 11, 2023
This is very informational. I’ve got a few ARs. All in 5.56. I’ve done some swapping of parts and now have a complete lower I wasn’t sure what to do with until now. I’ve always wanted to get into long range shooting and the 6.5 Grendel seems like a good choice for it. Thank you.
Copyright © 2024 Bear Creek Arsenal, LLC. All Rights Reserved.