In this guide, let's break down 6.5 Grendel vs 5.56 in detailed specs. Both rounds are popular ammo for personal defense, target shooting and hunting.
Here are their differences:
6.5 Grendel VS 5.56 - Key Differences

The 6.5 Grendel and 5.56 are two popular cartridge choices among firearms enthusiasts. Both cartridges are used for hunting and target shooting, but they have different ballistic performances.
When it comes to shooting at longer distances, the 6.5 Grendel is better than the 5.56 in most ways.

The 6.5 has more power and is better at penetrating targets. It's more powerful than the 5.56 in every way and it's even more accurate and performs better at longer distances than the 7.62x51mm.
The 6.5 Grendel boasts a flatter trajectory, longer effective range, and higher energy compared to the 5.56. The 5.56, on the other hand, is known for its lighter recoil, cheaper ammunition cost, and faster follow-up shots.
Understanding the difference in velocity, energy, and bullet drop between the two cartridges will help shooters make informed decisions when choosing between the 6.5 Grendel and 5.56.
6.5 Grendel vs. 5.56 Blackout Dimensions
Referenced thebiggamehuntingblog.com
Bullet | 5.56 | 6.5 Grendel |
---|---|---|
Bullet Diameter | 0.224" | 0.264" |
Neck Diameter | 0.253" | 0.293" |
Base Diameter | 0.378" | 0.44" |
Case Length | 1.76" | 1.52" |
Overall Length | 2.26" | 2.26" |
Standard Bullet Weight | 50 - 65 gr | 90 - 130 gr |
The 6.5 Grendel measures 2.26 inches in overall length and can handle a pressure of up to 52,000 psi. Its case length is 1.5 inches, its neck diameter is 0.471 inches, and its bullet diameter is 0.264 inches. The recommended powder charge for the 6.5 Grendel ranges from 20 to 28 grains.
Similarly, the 5.56 measures 2.26 inches in overall length and can withstand a pressure of up to 62,000 psi. It has a case length of 1.760 inches, a neck diameter of 0.378 inches, and a bullet diameter of 0.224 inches. The suggested powder charge for the 5.56 ranges from 26 to 40 grains.
6.5 Grendel VS 5.56 Ballistics
Referenced Sierra Bullets
The 6.5 Grendel's 123 grain bullet boasts a muzzle velocity of 2,580 fps, muzzle energy of 1,818 ft lbs, and a ballistic coefficient of 0.506. This allows it to maintain supersonic velocity at 1,000 yards and retain 400 ft lbs of energy.
In contrast, the 5.56 Ball M193 round's 55 grain bullet has a muzzle velocity of 3,265 fps, muzzle energy of 1,302 ft lbs, and a ballistic coefficient of 0.272. At 1,000 yards, its velocity drops below the speed of sound to 947 fps and its energy decreases to only 110 ft lbs.
The 6.5 Grendel is a special type of bullet that can be used for both protecting yourself and hunting animals. When used for self-defense, it is strong enough to stop a person who is threatening you if you aim correctly. If you're using it for hunting, the distance you can kill a deer depends on the type of bullet you use.
For example, a soft point bullet might not work well beyond 300 yards, but a special hunting bullet called the SST can kill a deer from over 400 yards away. However, it's important to remember that even a weaker bullet can still kill a deer if you aim it in the right spot.
6.5 Grendel Vs 5.56 Muzzle Velocity & Energy
The 223/5.56 NATO may have a faster muzzle velocity than most rounds, but the 6.5 Grendel reigns supreme in terms of muzzle energy.
Compare the performance of three rounds from Hornady - the Frontier 55 gr FMJ (M193 clone) for 5.56, the 55 gr V-MAX Varmint Express for 223 Remington, and the 123 gr SST for 6.5 Grendel. All three are excellent choices for target shooting or self-defense.
At the muzzle, the 223/5.56 bullets shoot down range at a speedy 3,240 fps, while the 6.5 Grendel lags behind at 2,580 fps. This disparity exists because 223/5.56 fires lighter bullets, whereas every factory load for 6.5 Grendel fires heavier projectiles with greater muzzle energy - 1,818 ft-lbs compared to 1,282 ft-lbs for the 223/5.56.
These design differences highlight the varied purposes of each cartridge. The 223 Rem and 5.56 NATO aim for high velocity with low recoil, relying on bullet fragmentation and hydrostatic shock, while the 6.5 Grendel prioritizes delivering large amounts of kinetic energy into the target with heavier bullets.
Keep in mind that barrel length greatly impacts muzzle energy and velocity. Manufacturers often provide ballistic data based on proofing barrels - typically 20” for 223/5.56 and 24” for 6.5 Grendel.
If you choose a shorter barrel for your AR-15 carbine, keep in mind that your downrange ballistics may differ from the above numbers."
6.5 Grendel VS 5.56 Cost
If you're on a budget, the 5.56 NATO is the better option for you. It's more affordable to shoot than the 6.5 Grendel. However, the cheaper 5.56 ammo still hits accurately and has half the recoil compared to the 6.5 Grendel.
When it comes to availability and cost, the 5.56 NATO wins. The 6.5 Grendel is still a high-end, niche cartridge with fewer manufacturers producing it compared to the hundreds of manufacturers that produce millions of rounds of 5.56 NATO every year.
New-brass 5.56 ammo can be found for about $0.68 per round, while match-grade ammo can be found for about $1.25 per round. The cheapest 6.5 Grendel rounds are at least $1.50 each, and match ammo for shooting at long distances can cost up to $4.50 per round. That's at least $70.00 for a 20-round box, which is not enough to fill a single magazine for high volume training.
Referenced The Firearm Blog
5.56 Ballistic Chart
Referenced The Firearm Blog
Hunting Applications
"When it comes to hunting, different rifles use different cartridges that are good at different things.
The 5.56 NATO/223 Rem is a great choice for hunting small animals like varmints. This is because it shoots in a flatter trajectory, which makes it good for shooting from a distance. But, it doesn't have enough power to kill medium to large game animals like deer, so it's not allowed in some states and provinces for hunting deer.
The 6.5 Grendel is great for hunting medium-sized animals like deer or antelope. Its heavier bullets have enough power to kill the animal from up to 400 yards away. While you could use the 6.5 Grendel to hunt small animals, most hunters prefer the 223 or 5.56 because they have less recoil and use lighter bullets.
While the 6.5 Grendel could technically be used to hunt an elk if you shoot it perfectly, it's better to use a cartridge like the 300 Winchester Magnum for large game like that.
So, in short, the 223/5.56 is good for small animals because of its flat trajectory and lightweight bullets, while the 6.5 is better for medium-sized animals like deer." There are also many moving target reticles designed for 5.56 in many rifle scope options
6.5 Grendel VS 5.56 Effective Range
Most people would agree that the 6.5 Grendel's maximum effective range is about 800 - 900 yards, making it a good choice for medium-size game hunting at ranges between 400 and 500 yards.
The 5.56 NATO, on the other hand, has a maximum effective range of 450 meters according to the U.S. Army. It remains lethal within a range of 275 to 300 yards. Shooters who use match-grade barrels of 20 inches or longer claim to be able to hit targets at up to 600 yards.
However, the bullet drop is so significant and the energy so low that it is only suitable for long-distance shooting challenges, not for hunting. A longer barrel configuration for this cartridge is not effective for hunting purposes.
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