5.56 vs 6.5 Grendel – Which One Will You Choose?

6.5 grendel vs 5.56-header
Alfred Mendoza

For AR-15 rifle lovers, the 5.56 NATO and Grendel 6.5 are the topmost cartridges that can debatably challenge each other when it comes to AR compatibility and versatility. So when Hornady claimed that the 6.5 Grendel is quite possibly the most efficient cartridge ever to be chambered in the AR platform, the 5.56 NATO fans begged to disagree.  

To see which ammo is better between 6.5 Grendel vs 5.56, our team prepared this in-depth comparison between the two.

The difference between the 6.5 Grendel and the 5.56 NATO is sometimes quite hard to notice. The Army’s favorite 5.56x45mm allows fast and accurate application of fire in close quarters and short distances. 

At the same time, the 6.5x39mm, according to many firearms enthusiasts, is a jack-of-all-trades that offers better power and light years better ballistic performance after adding a little recoil and weight from a 5.56. Aside from bullet size, muzzle velocity, and bullet energy, there are a lot more that these bullets have to offer.

Specification Chart

6.5 Grendel

  • Brand: Alexander Arms
  • Model: 6.5 Grendel
  • Bullet Size: 0.256 inches
  • Bullet Diameter: 0.264 inches
  • Shell Case Type: Rimless, bottleneck
  • Energy (per 200 yards): 1,383 ft-lbs
  • Velocity (per 200 yards): 2,278 ft/s
  • Muzzle Energy: 1,658 ft-lbs
  • Muzzle Velocity: 2,880 ft/s

5.56 NATO

  • Brand: NATO
  • Model: 5.56
  • Bullet Size: 0.224 inches
  • Bullet Diameter: 0.224 inches
  • Shell Case Type: Rimless tapered, bottleneck
  • Energy (per 200 yards): 856 ft-lbs
  • Velocity (per 200 yards): 2,493 ft/s
  • Muzzle Energy: 1,797 ft-lbs
  • Muzzle Velocity: 3,100 ft/s

Comprehensive Comparison

Grendel 6.5 & 5.56 Pricing

When it comes to affordability, the 5.56 takes a win over the 6.5 Grendel. The 6.5 Grendel is more expensive to shoot than the 5.56. Even so, the quality of the cheaper ammo isn’t compromised since it hits more accurately and has half the recoil than the 6.5 Grendel. So, if your budget is restricted, we suggest that you go for the 5.6 NATO.

AR-15 Compatibility

As mentioned earlier in this post, the 6.5 Grendel and 5.56 NATO ammo undeniably works best for AR platforms. Between 6.5 Grendel vs 5.56 NATO ammunition are compatible with the AR-15, but shooters want to know which works better for the AR-15. So, the team decided to test both in the shooting range. 

We noticed that during the test, the 5.56 shoots faster compared to the 6.5 Grendel because it has less recoil. Although the 5.56 works better than 6.5 Grendel in close range, the Grendel is more accurate than the 5.56 at longer ranges and hits harder. This compatibility test result is a draw.

AR 15

Long Range Shooting

Since the 6.5 Grendel was initially designed to extend the effective range of an AR-15, the 5.6 NATO falls short in this category. The Grendel does have a much longer effective range than any other AR-15 cartridge. 

Although the 6.5 Grendel, being a heavier bullet, has double the recoil and slightly less capacity than the 5.56, it is still more effective in long-range shooting than the 5.56, which has issues at longer ranges and barriers penetration.

Planning to get a new rifle? This TC Compass vs Ruger American comparison will help you decide.

Ballistics - 6.5 or 5.56?

Ballistically speaking, except for bullet drop, the 6.5 Grendel is more superior to the 5.56 when it comes to longer-range shooting. 

The 6.5 has a lower sectional density and has more power, has more excellent penetration capabilities on the game than the 5.6. The 6. Grendel is more potent than the 5.56 in all of its offerings, and it even has better long-range performance and accuracy than the 7.62x51mm.

Learn how to make ballistic gel here

bullet exploding

Hunting Capacity

For smaller game, both ammo would still be great to use. Although the 5.56 is arguably better for shooting varmints because the trajectory is flatter for the first few yards, the 6.5 walks over the 5.6 in long-range shooting. But if you are talking deer-sized game or larger, then a 556 is a little short. Although it can still be used to hunt raccoons and deers, the 6.5 Grendel works better because of low recoil, which helps in shot placement.

Looking for more hunting ammo? Check out 6.5 Creedmoor and 224 Valkyrie here.

Grendel 6.5 Pros & Cons



5.56 Pros & Cons



Grendel 6.5 or NATO 5.56 – Our Choice is...

In choosing between 6.5 Grendel vs 5.56, our choice is Grendel 6.5. Although the 6.5 Grendel is more expensive, it works better at long-range shootings and for larger games, has more energy, more range, and more firepower than the 5.6 NATO. But if you don’t mind much about hunting larger animals and in longer ranges, buying an affordable 5.6 NATO is relatively a good buy.

Another 6.5 Grendel comparison article: 300 Blackout vs. 6.5 Grendel Face-Off

6.5 Grendel

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6.5 Grendel

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