6.5 Grendel vs 6.8 SPC: What You Need To Know

6.5 Grendel vs 6.8 SPC
Alfred Mendoza

Fair warning: Discussing 6.5 Grendel vs 6.8 SPC is tricky business.

But if you expect us to steer clear of the topic, you are wrong. Both cartridges are worth hammering away because they can stretch out the capabilities of AR-15.

Curious about these two solid performers? Our team decided to put the two medium bore AR cartridges to the test to see how they fare against each other.

While most hunting ranges require similar kinetic energy and trajectory, the 6.5 Grendel outperforms 6.8 SPC with its aerodynamic capacity that allows it to be resistant to wind drift at ranges past 200 to 300 yards. The 6.5 Grendel also has a smaller bullet diameter, lesser bullet drop, better kinetic energy, and lesser free recoil compared to 6.8 SPC.

The 6.5 Grendel

  • Sectional density can reach up to .264
  • Achieves optimal state at 100 to 123 grains
  • Slightly higher knockback, but still mild
  • Better selection of bullets
  • More affordable

The 6.8 SPC

  • Sectional density can reach up to . 223
  • Achieves optimal state at 100 to 120 grains
  • Very mild knockback
  • Extensive bullet selection
  • More expensive

How Are They Similar?

There is an overlap between the performances of 6.5 Grendel and 6.8 SPC, so it is hard to take sides.  You can only notice the distinction when you go beyond 300 yards.

Here are some of their similarities:

  • Both demonstrate the same lethality as a hunting cartridge. Expect to wipe out a large game in just one hit with any of these cartridges.
  • Both cartridges cannot accommodate heavy bullets, which end up stuck in the cases.
  • They share the same history — the AR-15 and the .223 Remington (more on this later).
  • Both cartridges need an operator to use special bolts, magazines, and barrels.

In-Depth Comparison


As mentioned earlier, both 6.5 Grendel and 6.8 SPC have the same beginning. Civilian hunters who began utilizing the Ar-15 and .223 Remington cartridge during the latter part of the 20th century had encountered a few difficulties.

The cartridge and rifle combination was good enough for varmint/predator shooting, but there was a performance issue when it came to deer hunts.

Many sportsmen adore the rifle, so the .223 Remington cartridge had to take the back seat.


Bill Alexander was responsible for the existence of the 6.5 Grendel. He modified a 6.5 mm PPC Case and successfully created a handy shooting cartridge that really matched the AR platform in 2002. His creation is more reliable and more powerful than the .223 Remington without sacrificing versatility. It works efficiently for various purposes, from varmint and big game hunting to tactical and law enforcement. After he removed his trademark, Wilson Combat and other companies such as Brenton USA began crafting sporting rifles that utilize the cartridge.

The 6.8 Special Purpose Cartridge came into being when the IS Army Special Forces requested Remington Arms Company to develop a more aggressive stand-in to their 5.56x45mm Nato cartridge that would work in the M-4carbine. This new cartridge originated from a shortened.30 Remington case

Case Measurements


The two cartridges have the same length: 2.26 inches, which is also the maximum cartridge size an Ar-15 can accommodate. This means they both fit the rifle up to the ceiling.

When it comes to size, 6.8 SPC is evidently longer vs 6.5 mm cartridge.

The 6.8 SPC has an average length of 1.6765 inches with a range of 0.060 inches, about 0.36%. The paramount length is 1.686 inches. Bear in mind that the “trim” length is considered above average. It has a rim diameter of .433. Here are some of the best 6.8 SPC magazines

The average length for the 6.5 Grendel is 1.5097 inches. It also comes with a range of 0.0110 inches or (0.73%). The longest stretch is listed at 1.520. This means that the average length is ideal for the suggested trim length, which is -0.10 inch. Its rim diameter is .438”.

They differ in rim diameter because they come from different parent cartridges. They have almost the same case capacity, but the 6.8 SPC can hold more gunpowder.

Want to compare more ammunition? We recommend you check out our detailed .224 Valkyrie and 6.5 Grendel comparison.


Competition shooters hold the 6.5 Grendel with high regard, but that does not mean a round of 6.8 SPC is not capable of exhibiting excellent accuracy.

It is just that the 6.5 Grendel retains its precision for long-distance shooting since it has better trajectories and fewer bullet drops and wind shifts between 400 to 500 yards.

However, both have a comparable performance at normal hunting ranges. They are equal in fatality. 

bullet accuracy

If you don’t care about range and velocity, we see no reason you shouldn’t go with one or the other. But, if you do, then the Grendel would be your best bet.

Recommended article, Remington 700 vs 783: Is one better than the other?


Grendel ammo normally has weights beginning 90 grain to 130 grain. Due to a higher sectional density, they remain more intact on impact than the 6.8 bullet of the same weight. 

It shoots .264 bullets just like the 6.5 Creedmoor and .260 Remington, among others.

The 6.8 SPC utilizes the exact same diameter bullet that the .270 Winchester uses, but they differ in weight. It also has wider ammo availability.

bullet weight

It also uses 110 to 115 grain Sierra bullets in general, but there are selections in the 85 to 120-grain variety. That being said, it offers a broader assortment than the Grendel.

Both cartridges can’t perform well with heavier bullets. The heavier and longer bullets they are, the less gunpowder space, which translates to lower velocities. On the bright side, there are excellent factory ammo choices for both.


The 6.5 Grendel gets the optimum balance of velocity to bullet weight at around 100 to 123 grains. The 6.8 hits this balance in the 100 to 120-grain variety.

Moreover, the 6.5 Grendel can cater to a 123-grain bullet, which brings off an SD of .252. The 6.8 SPC, on the other hand, can accommodate a 120-grain bullet at most, which achieves an SD of .223.

As a gun enthusiast, you already have a good grasp of the advantages of high sectional densities. So you can tell that the clear winner here is the Grendel.


The 6.8 SPC is about thrice the price of the 6.5 Grendel. It does not take a math wiz to determine which one is more cost-efficient. Between the 6.8 SPC and 6.5 Grendel, the latter can help you stay within budget.


There are many factors in play when assessing felt recoil. It depends on the shooter themselves and the rifles used. It is easier to gauge free recoil energy. Both cartridges have mild kick back to begin with.

However, the 6.8 SPC has a bit of an edge. If you are a bit sensitive, you will like its  25% less free recoil energy.

However, even with more knockback, the Grendel is still much milder than other cartridges, such as the .308 Winchester and the 6.5 Creedmoor



Oh, this is where you see the unmistakable contrast. The distinction between distance and velocity can be seen when target shooting past 400 yards. For the 6.8 SPC, precision in long-range shooting is a tall order.

Compared to the 6.5 Grendel, which drops slowly and at a consistent pace without struggling to go against the wind. It delivers a cleaner and more precise shot in vast distances.

For individuals who like to shoot at targets at great distances, the 6.5 Grendel will give you more positive results.

Looking for more long range bullets? Here is 450 Bushmaster vs 45-70 Government compared.

Ballistic Terminal

Even the slight variance in external measurements leads to the fascinating differences between the two, especially in terms of ballistics. 

The 6.5 Grendel outperforms the 6.8 SPC in ballistics, especially at more considerable distances. Although, its advantages diminish or go away entirely with shorter barrels.

However, a round of 6.8 SPC can take down hunting varmints, feral hogs, and deer within a short to moderate distance.

ballistic terminal

It maintains its efficiency and performance if you typically use less than 16-inch barrelled guns. You could also get improved performance by utilizing handloads in 6.8 SPC II chambers.

On the other hand, you’ll have a hard time finding a 6.8 SPC ammo weighing more than 120 grains, but it is available. But the 6.5 Grendel’s maximum factory loaded ammo is 129 grains.

Winner: 6.8 SPC or 6.5 Grendel?

The Grendel is better than the 6.8 SPC by a small margin. But there is no reason to dog on the latter if you are not fond of using a firearm with a long barrel. Most 6.8 SPC versus 6.5 Grendel loadings will have nearly identical results until reaching 400 to 500 yards.

Since there is a thin line separating these cartridges, many sportsmen find it challenging which one better for their rifle. Evaluate your needs, barrel preferences, and the situations you will be in. From this, you can have a well-informed decision.

What’s next? If you want to browse through our recommended concealed carry pistol options, check out our Glock 19 vs M&P 9c comparison here.

Our #1 Recommendation

6.5 Grendel

2 thoughts on “6.5 Grendel vs 6.8 SPC: What You Need To Know”

  1. Unfortunately the ammo companies are stuck with no other option than to make their loads compatible with the original spec 1 6.8 spc chamber which was prone to pressure spikes due to a short freebore. Because of this the over the counter ammo for 6.8 is watered down. To my knowledge no manufacturer is still producing 6.8 in the original chamber design and hasn’t for quite a while. The newer spec II and various other chambers are designed to handle the hotter loads and not have the pressure spike issues of the original chamber- way to go Remington. I own and reload for both 6.8 spc and 6.5 G. I firmly believe the 6.8 to be the better cartridge. With the 6.5 you will need a longer barrel preferably over 20”. This is not the case with the 6.8. The 6.8 only needs 16” barrel to send a 95 grain bullet to 2900 FPS with hand loads. The 6.5 G ammo is already near max with some performance factory loads and if you push it too far the bolt could break. The bolts are another issue for these calibers. You will need to use a quality bolt for each utilizing strong alloys. This is especially true for the wider case head for the 6.5. It leaves less metal around the bolt face resulting in a weaker bolt that is easier to damage. Accuracy is a tie inside 350 yards which is the furthest I would shoot either at a living target. If you’re into punching small holes in paper then the 6.5 would do fine out to long ranges, but that doesn’t mean you will have the velocity necessary for reliable expansion and penetration to humanly kill an animal. I hunt with my rifles and terminal performance is a huge factor. The 6.8 with Barnes or Cavity Black copper bullets has never failed me. Extremely accurate to the point of one ragged hole at 100 yards. The wound channels are impressive but not too destructive, and the bullets always exit. I rarely have to track animals down after being hit and most drop on impact or within 30 yards. I still like my 6.5, but my 6.8’s see a lot more action because of their performance. If you hunt and don’t mind making your own ammunition the 6.8 is extremely hard to beat. If you only want a target gun and don’t mind a longer barrel the 6.5 might be a good option, but I would look at the .224 Valkyrie before going with 6.5 grendel for a target gun. It’s hard to push the performance of a cartridge when you’re limited to an AR-15 platform. The Biggest restrictions are cartridge overall length, pressure, and case head diameter. The 6.8 stays safely inside these limits and does so while maintaining useful performance with a short barrel. Another issue I would like to address is the bullets weights used in most test are not ideal for the 6.8 spc. 85-105 grain bullets are where the 6.8 shines.

  2. Good comparison! I have both and use the 6.8SPC for moderate range, and the 6.5 G for longer distance hunts. Great article keep up the good work. Kill them Texas Hogs too.

Leave a Comment

Your email address will not be published. Required fields are marked *